/* Modifed by BL to namespace the functions */

/*

DISCLAIMER: THESE JAVASCRIPT FUNCTIONS ARE SUPPLIED 'AS IS', WITH 
NO WARRANTY EXPRESSED OR IMPLIED. YOU USE THEM AT YOUR OWN RISK. 
NEITHER PAUL STEPHENS NOR PC PLUS MAGAZINE ACCEPTS ANY LIABILITY FOR 
ANY LOSS OR DAMAGE RESULTING FROM THEIR USE, HOWEVER CAUSED. 

Paul Stephens' NetScape-based cookie-handling library

http://web.ukonline.co.uk/paul.stephens/index.htm

TO USE THIS LIBRARY, INSERT ITS CONTENTS IN A <script></script> BLOCK IN THE 
<HEAD> SECTION OF YOUR WEB PAGE SOURCE, BEFORE ANY OTHER JAVASCRIPT ROUTINES.

Feel free to use this code, but please leave this comment block in.

*/

var Cookies = {

    setCookie: function(name, value, lifespan, access_path) {
          
        var cookietext = name + "=" + escape(value)  
        if (lifespan != null) {  
            var today=new Date()     
            var expiredate = new Date()      
            expiredate.setTime(today.getTime() + 1000*60*60*24*lifespan)
            cookietext += "; expires=" + expiredate.toGMTString()
        }
        if (access_path != null) { 
            cookietext += "; PATH="+access_path 
        }
        document.cookie = cookietext 
        return null  
    },


    setDatedCookie: function(name, value, expire, access_path) {
        var cookietext = name + "=" + escape(value)
                + ((expire == null) ? "" : ("; expires=" + expire.toGMTString()))
        if (access_path != null) { 
            cookietext += "; PATH="+access_path 
        }
        document.cookie = cookietext 
        return null        
    },


    getCookie: function(Name) {
        var search = Name + "="                       
        var CookieString = document.cookie            
        var result = null                               
        if (CookieString.length > 0) {                
            offset = CookieString.indexOf(search)       
            if (offset != -1) {                         
                offset += search.length                   
                end = CookieString.indexOf(";", offset)   
                if (end == -1)                            
                    end = CookieString.length               
                result = unescape(CookieString.substring(offset, end))         
                                                
            } 
        }
        return result                                
    },


    deleteCookie: function(name) {
        Cookies.setCookie(name, "Deleted", -1)
    }
    
}

var pc = navigator.userAgent.toLowerCase();
var ie4_win = (pc.indexOf("win")!=-1) && (pc.indexOf("msie") != -1)
    && (parseInt(navigator.appVersion) >= 4);
var checked = false;

// only builds based upon gecko later than Jan 8th support the selectionStart, selectionEnd properly
var is_gecko = pc.indexOf("gecko/") != -1 &&
    parseFloat(pc.substring(pc.indexOf("gecko/") + 6, pc.indexOf("gecko/") + 14)) > 20030108;

function checkPost() {
    if (arguments.length > 0) { window.onbeforeunload = null; }

	if (!checked) {
        checked = true;
        return true;
    }
    return false;
}

function insertAtCursor(text, ta) {
    var end = 0;
    var scrollTop = ta.scrollTop;
    
    ta.focus();
    
    if (document.selection && document.selection.createRange().parentElement().tagName == 'TEXTAREA') {
        var selected = document.selection.createRange().text;
        
        // now determine the cursor position
        end = getSelectionRangeEnd(ta);
         
        // update text
        document.selection.createRange().text = selected + text;            
        // update end position
        end += text.length;
    } 
    else if (typeof(ta.selectionStart) != 'undefined' && typeof(ta.selectionEnd) != 'undefined') {
        var selLength = ta.textLength;
        var selStart = ta.selectionStart;
        var selEnd = ta.selectionEnd;
        if (selEnd == 1 || selEnd == 2) {
            selEnd = selLength;
        }
        var s1 = (ta.value).substring(0, selEnd);
        var s2 = (ta.value).substring(selEnd, selLength);
        
        // update text
        ta.value = s1 + text + s2;            
        // update end position
        end = selEnd + text.length;
    } 
    else {
        ta.value += text;
    }
    
    if (end > 0) { 
        setCaretTo(ta, end, scrollTop); 
    }
}

function styleTag(tag, endtag, ta) {
    var end = 0;
    var scrollTop = ta.scrollTop;

    if (document.selection) {
        if (document.selection.createRange().parentElement().tagName == 'TEXTAREA') {
            var selected = document.selection.createRange().text;

            // now determine the cursor position
            end = getSelectionRangeEnd(ta);

            // r is an array
            var r = _markupText(selected, tag, endtag);
            // update text
            document.selection.createRange().text = r[0];
            // update end position
            end += r[1];
        }
    }
    else if (typeof(ta.selectionStart) != 'undefined' && typeof(ta.selectionEnd) != 'undefined') {
        if (ta.selectionStart == ta.selectionEnd) {
            return;
        }
        var selLength = ta.textLength;
        var selStart = ta.selectionStart;
        var selEnd = ta.selectionEnd;
        if (selEnd == 1 || selEnd == 2) {
            selEnd = selLength;
        }
        var s1 = (ta.value).substring(0, selStart);
        var s2 = (ta.value).substring(selStart, selEnd);
        var s3 = (ta.value).substring(selEnd, selLength);

        // r is an array
        var r = _markupText(s2, tag, endtag);
        // update text
        ta.value = s1 + r[0] + s3;
        // update end position
        end = selEnd + r[1];
    }
    else {
        return;
    }

    if (end > 0) {
        setCaretTo(ta, end, scrollTop);
    }
}

function _markupText(text, tag, endtag) {
    // trim off leading whitespace from selection (includes newlines)
    var r = trimLeadingSpace(text);
    text = r[0];
    var removeSpace = r[1];

    // trim off trailing whitespace from selection (includes newlines)
    r = trimTrailingSpace(text);
    text = r[0];
    var addSpace = r[1];

    // determine if selection crosses multiple lines
    var addedCharacters = 0;

    if (text.indexOf('\n') > 0) {
        // wrap whole lines in the tag
        var lines = text.split('\n');
        var newText = '';
        for (var i = 0; i < lines.length; i++) {
            var line = lines[i];

            r = trimLeadingSpace(line);
            line = r[0];
            var leadingSpaces = r[1];

            // trim off trailing whitespace from selection (includes newlines)
            r = trimTrailingSpace(line);
            line = r[0];
            var trailingSpaces = r[1];

            if (line == '') {
                newText += leadingSpaces + line + trailingSpaces;
            }
            else {
                newText += leadingSpaces + tag + line + endtag + trailingSpaces;
                addedCharacters += (tag.length + endtag.length);
            }

            if (i < lines.length -1) {
                newText += '\n';
            }
        }
        text = removeSpace + newText + addSpace;
    }
    else {
        text = removeSpace + tag + text + endtag + addSpace;
    }

    r = new Array(2);
    r[0] = text;
    r[1] = addedCharacters;

    return r;
}

function trimLeadingSpace(text) {
    var removeSpace = "";
    while (text.length > 0 && 
           (text.charAt(0) == ' ' || 
            text.charAt(0) == '\n' ||
            text.charAt(0) == '\r')) 
    {
        removeSpace += text.charAt(0);
        text = text.substring(1);
    }
    
    var r = new Array(2);
    r[0] = text;
    r[1] = removeSpace;
    return r;
}

function trimTrailingSpace(text) {
    var addSpace = "";
    while (text.length > 0 && 
           (text.charAt(text.length-1) == ' ' || 
            text.charAt(text.length-1) == '\n' || 
           text.charAt(text.length-1) == '\r')) 
    {
        addSpace += text.charAt(text.length-1);        
        text = text.substring(0, text.length-1);
    }
    
    var r = new Array(2);
    r[0] = text;
    r[1] = addSpace;
    return r;
}

function getSelectionRangeText(ta) {
    if (document.selection) {
        // The current selection
        return document.selection.createRange().text;
    }
    else if (is_gecko) {
        var start = ta.selectionStart;
        var end   = ta.selectionEnd;
        return ta.value.substr(start, end-start);
    }
    else {
        return '';
    }
}

function getSelectionRangeEnd(ta) {
    if (document.selection) { 
        // The current selection 
        var range = document.selection.createRange(); 
        // We'll use this as a 'dummy' 
        var stored_range = range.duplicate(); 
        // Select all text 
        stored_range.moveToElementText(ta); 
        // Now move 'dummy' end point to end point of original range 
        stored_range.setEndPoint('EndToEnd', range); 
        
        // Now we can calculate start and end points
        var start = stored_range.text.length - range.text.length; 
        return start + range.text.length;
    }
    else if (is_gecko) {
        return ta.selectionEnd;
    }
    else {
        return 0;
    }
}
function setCaretTo(ta, pos, scrollTop) { 
    ta.focus();
    if (ta.createTextRange) {         
        // we need to determine the number of \r\n in IE because while they are two separate
        // characters they are treated as one for the purposes of position
        var i = 0;
        var count = 0;
        var text = ta.value;
        while (i > -1 && i < pos) {
            i = text.indexOf("\r\n", i);
            if (i >= 0) {
                count++;
                i += 2;
            }
        }
        // knock one off of count 
        if (count > 1) {
            count--;
        }
        
        // position cursor
        var range = ta.createTextRange();        
        range.move("character", (pos - count)); 
        range.select(); 
    } 
    else if (ta.selectionStart) {
        ta.setSelectionRange(pos, pos);        
    }
    
    // scroll to the same location that the textarea was previously scrolled to
    if (scrollTop > 0) {
        ta.scrollTop = scrollTop;
    }
}

function caret(ta) {
    if (ie4_win && ta.createTextRange &&
            document.selection.createRange().parentElement().tagName == 'TEXTAREA')
    {
        ta.caretPos = document.selection.createRange().duplicate();
    }
}

// This function returns the name of a given function. It does this by
// converting the function to a string, then using a regular expression
// to extract the function name from the resulting code.
function funcname(f) {
    var s = f.toString().match(/function (\w*)/)[1];
    if ((s == null) || (s.length == 0)) return "anonymous";
    return s;
}

// This function returns a string that contains a "stack trace."
function stacktrace() {
    var s = "";  // This is the string we'll return.
    // Loop through the stack of functions, using the caller property of
    // one arguments object to refer to the next arguments object on the
    // stack.
    for(var a = arguments.caller; a != null; a = a.caller) {
        // Add the name of the current function to the return value.
        s += funcname(a.callee) + "\n";

        // Because of a bug in Navigator 4.0, we need this line to break.
        // a.caller will equal a rather than null when we reach the end
        // of the stack. The following line works around this.
        if (a.caller == a) break;
    }
    return s;
}

function printStackTrace() {
    alert('stack trace is ' + stacktrace());
}

// TODO: this shouldn't be conceptually tied to a "row"

// "hashmap" for the row elements so we can remember the style before switching to the hilite one
var hoverElements = new Array();

function onhover(el) {
    if (typeof(el) == "undefined" || typeof(el.className) != "undefined") {
        return;
    }
    hoverElements[el] = el.className;
    el.className = el.className + " hilite";
}

function onhoverbyclass(el, cl) {
    hoverElements[el] = el.className;
    el.className = el.className + " " + cl;
}

function offhover(el) {
    if (hoverElements[el]) {
        el.className = hoverElements[el];
    }
}

function onclick(el) {
    onhover(el);
}

/* todo: not working right now! */
function clearhover(el) {
    el.className = el.className.replace(/hilite/g, "")
}
/*  Prototype JavaScript framework, version 1.5.1
 *  (c) 2005-2007 Sam Stephenson
 *
 *  Prototype is freely distributable under the terms of an MIT-style license.
 *  For details, see the Prototype web site: http://www.prototypejs.org/
 *
/*--------------------------------------------------------------------------*/

var Prototype = {
  Version: '1.5.1',

  Browser: {
    IE:     !!(window.attachEvent && !window.opera),
    Opera:  !!window.opera,
    WebKit: navigator.userAgent.indexOf('AppleWebKit/') > -1,
    Gecko:  navigator.userAgent.indexOf('Gecko') > -1 && navigator.userAgent.indexOf('KHTML') == -1
  },

  BrowserFeatures: {
    XPath: !!document.evaluate,
    ElementExtensions: !!window.HTMLElement,
    SpecificElementExtensions:
      (document.createElement('div').__proto__ !==
       document.createElement('form').__proto__)
  },

  ScriptFragment: '<script[^>]*>([\u0001-\uFFFF]*?)</script>',
  JSONFilter: /^\/\*-secure-\s*(.*)\s*\*\/\s*$/,

  emptyFunction: function() { },
  K: function(x) { return x }
}

var Class = {
  create: function() {
    return function() {
      this.initialize.apply(this, arguments);
    }
  }
}

var Abstract = new Object();

Object.extend = function(destination, source) {
  for (var property in source) {
    destination[property] = source[property];
  }
  return destination;
}

Object.extend(Object, {
  inspect: function(object) {
    try {
      if (object === undefined) return 'undefined';
      if (object === null) return 'null';
      return object.inspect ? object.inspect() : object.toString();
    } catch (e) {
      if (e instanceof RangeError) return '...';
      throw e;
    }
  },

  toJSON: function(object) {
    var type = typeof object;
    switch(type) {
      case 'undefined':
      case 'function':
      case 'unknown': return;
      case 'boolean': return object.toString();
    }
    if (object === null) return 'null';
    if (object.toJSON) return object.toJSON();
    if (object.ownerDocument === document) return;
    var results = [];
    for (var property in object) {
      var value = Object.toJSON(object[property]);
      if (value !== undefined)
        results.push(property.toJSON() + ': ' + value);
    }
    return '{' + results.join(', ') + '}';
  },

  keys: function(object) {
    var keys = [];
    for (var property in object)
      keys.push(property);
    return keys;
  },

  values: function(object) {
    var values = [];
    for (var property in object)
      values.push(object[property]);
    return values;
  },

  clone: function(object) {
    return Object.extend({}, object);
  }
});

Function.prototype.bind = function() {
  var __method = this, args = $A(arguments), object = args.shift();
  return function() {
    return __method.apply(object, args.concat($A(arguments)));
  }
}

Function.prototype.bindAsEventListener = function(object) {
  var __method = this, args = $A(arguments), object = args.shift();
  return function(event) {
    return __method.apply(object, [event || window.event].concat(args));
  }
}

Object.extend(Number.prototype, {
  toColorPart: function() {
    return this.toPaddedString(2, 16);
  },

  succ: function() {
    return this + 1;
  },

  times: function(iterator) {
    $R(0, this, true).each(iterator);
    return this;
  },

  toPaddedString: function(length, radix) {
    var string = this.toString(radix || 10);
    return '0'.times(length - string.length) + string;
  },

  toJSON: function() {
    return isFinite(this) ? this.toString() : 'null';
  }
});

Date.prototype.toJSON = function() {
  return '"' + this.getFullYear() + '-' +
    (this.getMonth() + 1).toPaddedString(2) + '-' +
    this.getDate().toPaddedString(2) + 'T' +
    this.getHours().toPaddedString(2) + ':' +
    this.getMinutes().toPaddedString(2) + ':' +
    this.getSeconds().toPaddedString(2) + '"';
};

var Try = {
  these: function() {
    var returnValue;

    for (var i = 0, length = arguments.length; i < length; i++) {
      var lambda = arguments[i];
      try {
        returnValue = lambda();
        break;
      } catch (e) {}
    }

    return returnValue;
  }
}

/*--------------------------------------------------------------------------*/

var PeriodicalExecuter = Class.create();
PeriodicalExecuter.prototype = {
  initialize: function(callback, frequency) {
    this.callback = callback;
    this.frequency = frequency;
    this.currentlyExecuting = false;

    this.registerCallback();
  },

  registerCallback: function() {
    this.timer = setInterval(this.onTimerEvent.bind(this), this.frequency * 1000);
  },

  stop: function() {
    if (!this.timer) return;
    clearInterval(this.timer);
    this.timer = null;
  },

  onTimerEvent: function() {
    if (!this.currentlyExecuting) {
      try {
        this.currentlyExecuting = true;
        this.callback(this);
      } finally {
        this.currentlyExecuting = false;
      }
    }
  }
}
Object.extend(String, {
  interpret: function(value) {
    return value == null ? '' : String(value);
  },
  specialChar: {
    '\b': '\\b',
    '\t': '\\t',
    '\n': '\\n',
    '\f': '\\f',
    '\r': '\\r',
    '\\': '\\\\'
  }
});

Object.extend(String.prototype, {
  gsub: function(pattern, replacement) {
    var result = '', source = this, match;
    replacement = arguments.callee.prepareReplacement(replacement);

    while (source.length > 0) {
      if (match = source.match(pattern)) {
        result += source.slice(0, match.index);
        result += String.interpret(replacement(match));
        source  = source.slice(match.index + match[0].length);
      } else {
        result += source, source = '';
      }
    }
    return result;
  },

  sub: function(pattern, replacement, count) {
    replacement = this.gsub.prepareReplacement(replacement);
    count = count === undefined ? 1 : count;

    return this.gsub(pattern, function(match) {
      if (--count < 0) return match[0];
      return replacement(match);
    });
  },

  scan: function(pattern, iterator) {
    this.gsub(pattern, iterator);
    return this;
  },

  truncate: function(length, truncation) {
    length = length || 30;
    truncation = truncation === undefined ? '...' : truncation;
    return this.length > length ?
      this.slice(0, length - truncation.length) + truncation : this;
  },

  strip: function() {
    return this.replace(/^\s+/, '').replace(/\s+$/, '');
  },

  stripTags: function() {
    return this.replace(/<\/?[^>]+>/gi, '');
  },

  stripScripts: function() {
    return this.replace(new RegExp(Prototype.ScriptFragment, 'img'), '');
  },

  extractScripts: function() {
    var matchAll = new RegExp(Prototype.ScriptFragment, 'img');
    var matchOne = new RegExp(Prototype.ScriptFragment, 'im');
    return (this.match(matchAll) || []).map(function(scriptTag) {
      return (scriptTag.match(matchOne) || ['', ''])[1];
    });
  },

  evalScripts: function() {
    return this.extractScripts().map(function(script) { return eval(script) });
  },

  escapeHTML: function() {
    var self = arguments.callee;
    self.text.data = this;
    return self.div.innerHTML;
  },

  unescapeHTML: function() {
    var div = document.createElement('div');
    div.innerHTML = this.stripTags();
    return div.childNodes[0] ? (div.childNodes.length > 1 ?
      $A(div.childNodes).inject('', function(memo, node) { return memo+node.nodeValue }) :
      div.childNodes[0].nodeValue) : '';
  },

  toQueryParams: function(separator) {
    var match = this.strip().match(/([^?#]*)(#.*)?$/);
    if (!match) return {};

    return match[1].split(separator || '&').inject({}, function(hash, pair) {
      if ((pair = pair.split('='))[0]) {
        var key = decodeURIComponent(pair.shift());
        var value = pair.length > 1 ? pair.join('=') : pair[0];
        if (value != undefined) value = decodeURIComponent(value);

        if (key in hash) {
          if (hash[key].constructor != Array) hash[key] = [hash[key]];
          hash[key].push(value);
        }
        else hash[key] = value;
      }
      return hash;
    });
  },

  toArray: function() {
    return this.split('');
  },

  succ: function() {
    return this.slice(0, this.length - 1) +
      String.fromCharCode(this.charCodeAt(this.length - 1) + 1);
  },

  times: function(count) {
    var result = '';
    for (var i = 0; i < count; i++) result += this;
    return result;
  },

  camelize: function() {
    var parts = this.split('-'), len = parts.length;
    if (len == 1) return parts[0];

    var camelized = this.charAt(0) == '-'
      ? parts[0].charAt(0).toUpperCase() + parts[0].substring(1)
      : parts[0];

    for (var i = 1; i < len; i++)
      camelized += parts[i].charAt(0).toUpperCase() + parts[i].substring(1);

    return camelized;
  },

  capitalize: function() {
    return this.charAt(0).toUpperCase() + this.substring(1).toLowerCase();
  },

  underscore: function() {
    return this.gsub(/::/, '/').gsub(/([A-Z]+)([A-Z][a-z])/,'#{1}_#{2}').gsub(/([a-z\d])([A-Z])/,'#{1}_#{2}').gsub(/-/,'_').toLowerCase();
  },

  dasherize: function() {
    return this.gsub(/_/,'-');
  },

  inspect: function(useDoubleQuotes) {
    var escapedString = this.gsub(/[\x00-\x1f\\]/, function(match) {
      var character = String.specialChar[match[0]];
      return character ? character : '\\u00' + match[0].charCodeAt().toPaddedString(2, 16);
    });
    if (useDoubleQuotes) return '"' + escapedString.replace(/"/g, '\\"') + '"';
    return "'" + escapedString.replace(/'/g, '\\\'') + "'";
  },

  toJSON: function() {
    return this.inspect(true);
  },

  unfilterJSON: function(filter) {
    return this.sub(filter || Prototype.JSONFilter, '#{1}');
  },

  evalJSON: function(sanitize) {
    var json = this.unfilterJSON();
    try {
      if (!sanitize || (/^("(\\.|[^"\\\n\r])*?"|[,:{}\[\]0-9.\-+Eaeflnr-u \n\r\t])+?$/.test(json)))
        return eval('(' + json + ')');
    } catch (e) { }
    throw new SyntaxError('Badly formed JSON string: ' + this.inspect());
  },

  include: function(pattern) {
    return this.indexOf(pattern) > -1;
  },

  startsWith: function(pattern) {
    return this.indexOf(pattern) === 0;
  },

  endsWith: function(pattern) {
    var d = this.length - pattern.length;
    return d >= 0 && this.lastIndexOf(pattern) === d;
  },

  empty: function() {
    return this == '';
  },

  blank: function() {
    return /^\s*$/.test(this);
  }
});

if (Prototype.Browser.WebKit || Prototype.Browser.IE) Object.extend(String.prototype, {
  escapeHTML: function() {
    return this.replace(/&/g,'&amp;').replace(/</g,'&lt;').replace(/>/g,'&gt;');
  },
  unescapeHTML: function() {
    return this.replace(/&amp;/g,'&').replace(/&lt;/g,'<').replace(/&gt;/g,'>');
  }
});

String.prototype.gsub.prepareReplacement = function(replacement) {
  if (typeof replacement == 'function') return replacement;
  var template = new Template(replacement);
  return function(match) { return template.evaluate(match) };
}

String.prototype.parseQuery = String.prototype.toQueryParams;

Object.extend(String.prototype.escapeHTML, {
  div:  document.createElement('div'),
  text: document.createTextNode('')
});

with (String.prototype.escapeHTML) div.appendChild(text);

var Template = Class.create();
Template.Pattern = /(^|.|\r|\n)(#\{(.*?)\})/;
Template.prototype = {
  initialize: function(template, pattern) {
    this.template = template.toString();
    this.pattern  = pattern || Template.Pattern;
  },

  evaluate: function(object) {
    return this.template.gsub(this.pattern, function(match) {
      var before = match[1];
      if (before == '\\') return match[2];
      return before + String.interpret(object[match[3]]);
    });
  }
}

var $break = {}, $continue = new Error('"throw $continue" is deprecated, use "return" instead');

var Enumerable = {
  each: function(iterator) {
    var index = 0;
    try {
      this._each(function(value) {
        iterator(value, index++);
      });
    } catch (e) {
      if (e != $break) throw e;
    }
    return this;
  },

  eachSlice: function(number, iterator) {
    var index = -number, slices = [], array = this.toArray();
    while ((index += number) < array.length)
      slices.push(array.slice(index, index+number));
    return slices.map(iterator);
  },

  all: function(iterator) {
    var result = true;
    this.each(function(value, index) {
      result = result && !!(iterator || Prototype.K)(value, index);
      if (!result) throw $break;
    });
    return result;
  },

  any: function(iterator) {
    var result = false;
    this.each(function(value, index) {
      if (result = !!(iterator || Prototype.K)(value, index))
        throw $break;
    });
    return result;
  },

  collect: function(iterator) {
    var results = [];
    this.each(function(value, index) {
      results.push((iterator || Prototype.K)(value, index));
    });
    return results;
  },

  detect: function(iterator) {
    var result;
    this.each(function(value, index) {
      if (iterator(value, index)) {
        result = value;
        throw $break;
      }
    });
    return result;
  },

  findAll: function(iterator) {
    var results = [];
    this.each(function(value, index) {
      if (iterator(value, index))
        results.push(value);
    });
    return results;
  },

  grep: function(pattern, iterator) {
    var results = [];
    this.each(function(value, index) {
      var stringValue = value.toString();
      if (stringValue.match(pattern))
        results.push((iterator || Prototype.K)(value, index));
    })
    return results;
  },

  include: function(object) {
    var found = false;
    this.each(function(value) {
      if (value == object) {
        found = true;
        throw $break;
      }
    });
    return found;
  },

  inGroupsOf: function(number, fillWith) {
    fillWith = fillWith === undefined ? null : fillWith;
    return this.eachSlice(number, function(slice) {
      while(slice.length < number) slice.push(fillWith);
      return slice;
    });
  },

  inject: function(memo, iterator) {
    this.each(function(value, index) {
      memo = iterator(memo, value, index);
    });
    return memo;
  },

  invoke: function(method) {
    var args = $A(arguments).slice(1);
    return this.map(function(value) {
      return value[method].apply(value, args);
    });
  },

  max: function(iterator) {
    var result;
    this.each(function(value, index) {
      value = (iterator || Prototype.K)(value, index);
      if (result == undefined || value >= result)
        result = value;
    });
    return result;
  },

  min: function(iterator) {
    var result;
    this.each(function(value, index) {
      value = (iterator || Prototype.K)(value, index);
      if (result == undefined || value < result)
        result = value;
    });
    return result;
  },

  partition: function(iterator) {
    var trues = [], falses = [];
    this.each(function(value, index) {
      ((iterator || Prototype.K)(value, index) ?
        trues : falses).push(value);
    });
    return [trues, falses];
  },

  pluck: function(property) {
    var results = [];
    this.each(function(value, index) {
      results.push(value[property]);
    });
    return results;
  },

  reject: function(iterator) {
    var results = [];
    this.each(function(value, index) {
      if (!iterator(value, index))
        results.push(value);
    });
    return results;
  },

  sortBy: function(iterator) {
    return this.map(function(value, index) {
      return {value: value, criteria: iterator(value, index)};
    }).sort(function(left, right) {
      var a = left.criteria, b = right.criteria;
      return a < b ? -1 : a > b ? 1 : 0;
    }).pluck('value');
  },

  toArray: function() {
    return this.map();
  },

  zip: function() {
    var iterator = Prototype.K, args = $A(arguments);
    if (typeof args.last() == 'function')
      iterator = args.pop();

    var collections = [this].concat(args).map($A);
    return this.map(function(value, index) {
      return iterator(collections.pluck(index));
    });
  },

  size: function() {
    return this.toArray().length;
  },

  inspect: function() {
    return '#<Enumerable:' + this.toArray().inspect() + '>';
  }
}

Object.extend(Enumerable, {
  map:     Enumerable.collect,
  find:    Enumerable.detect,
  select:  Enumerable.findAll,
  member:  Enumerable.include,
  entries: Enumerable.toArray
});
var $A = Array.from = function(iterable) {
  if (!iterable) return [];
  if (iterable.toArray) {
    return iterable.toArray();
  } else {
    var results = [];
    for (var i = 0, length = iterable.length; i < length; i++)
      results.push(iterable[i]);
    return results;
  }
}

if (Prototype.Browser.WebKit) {
  $A = Array.from = function(iterable) {
    if (!iterable) return [];
    if (!(typeof iterable == 'function' && iterable == '[object NodeList]') &&
      iterable.toArray) {
      return iterable.toArray();
    } else {
      var results = [];
      for (var i = 0, length = iterable.length; i < length; i++)
        results.push(iterable[i]);
      return results;
    }
  }
}

Object.extend(Array.prototype, Enumerable);

if (!Array.prototype._reverse)
  Array.prototype._reverse = Array.prototype.reverse;

Object.extend(Array.prototype, {
  _each: function(iterator) {
    for (var i = 0, length = this.length; i < length; i++)
      iterator(this[i]);
  },

  clear: function() {
    this.length = 0;
    return this;
  },

  first: function() {
    return this[0];
  },

  last: function() {
    return this[this.length - 1];
  },

  compact: function() {
    return this.select(function(value) {
      return value != null;
    });
  },

  flatten: function() {
    return this.inject([], function(array, value) {
      return array.concat(value && value.constructor == Array ?
        value.flatten() : [value]);
    });
  },

  without: function() {
    var values = $A(arguments);
    return this.select(function(value) {
      return !values.include(value);
    });
  },

  indexOf: function(object) {
    for (var i = 0, length = this.length; i < length; i++)
      if (this[i] == object) return i;
    return -1;
  },

  reverse: function(inline) {
    return (inline !== false ? this : this.toArray())._reverse();
  },

  reduce: function() {
    return this.length > 1 ? this : this[0];
  },

  uniq: function(sorted) {
    return this.inject([], function(array, value, index) {
      if (0 == index || (sorted ? array.last() != value : !array.include(value)))
        array.push(value);
      return array;
    });
  },

  clone: function() {
    return [].concat(this);
  },

  size: function() {
    return this.length;
  },

  inspect: function() {
    return '[' + this.map(Object.inspect).join(', ') + ']';
  },

  toJSON: function() {
    var results = [];
    this.each(function(object) {
      var value = Object.toJSON(object);
      if (value !== undefined) results.push(value);
    });
    return '[' + results.join(', ') + ']';
  }
});

Array.prototype.toArray = Array.prototype.clone;

function $w(string) {
  string = string.strip();
  return string ? string.split(/\s+/) : [];
}

if (Prototype.Browser.Opera){
  Array.prototype.concat = function() {
    var array = [];
    for (var i = 0, length = this.length; i < length; i++) array.push(this[i]);
    for (var i = 0, length = arguments.length; i < length; i++) {
      if (arguments[i].constructor == Array) {
        for (var j = 0, arrayLength = arguments[i].length; j < arrayLength; j++)
          array.push(arguments[i][j]);
      } else {
        array.push(arguments[i]);
      }
    }
    return array;
  }
}
var Hash = function(object) {
  if (object instanceof Hash) this.merge(object);
  else Object.extend(this, object || {});
};

Object.extend(Hash, {
  toQueryString: function(obj) {
    var parts = [];
    parts.add = arguments.callee.addPair;

    this.prototype._each.call(obj, function(pair) {
      if (!pair.key) return;
      var value = pair.value;

      if (value && typeof value == 'object') {
        if (value.constructor == Array) value.each(function(value) {
          parts.add(pair.key, value);
        });
        return;
      }
      parts.add(pair.key, value);
    });

    return parts.join('&');
  },

  toJSON: function(object) {
    var results = [];
    this.prototype._each.call(object, function(pair) {
      var value = Object.toJSON(pair.value);
      if (value !== undefined) results.push(pair.key.toJSON() + ': ' + value);
    });
    return '{' + results.join(', ') + '}';
  }
});

Hash.toQueryString.addPair = function(key, value, prefix) {
  key = encodeURIComponent(key);
  if (value === undefined) this.push(key);
  else this.push(key + '=' + (value == null ? '' : encodeURIComponent(value)));
}

Object.extend(Hash.prototype, Enumerable);
Object.extend(Hash.prototype, {
  _each: function(iterator) {
    for (var key in this) {
      var value = this[key];
      if (value && value == Hash.prototype[key]) continue;

      var pair = [key, value];
      pair.key = key;
      pair.value = value;
      iterator(pair);
    }
  },

  keys: function() {
    return this.pluck('key');
  },

  values: function() {
    return this.pluck('value');
  },

  merge: function(hash) {
    return $H(hash).inject(this, function(mergedHash, pair) {
      mergedHash[pair.key] = pair.value;
      return mergedHash;
    });
  },

  remove: function() {
    var result;
    for(var i = 0, length = arguments.length; i < length; i++) {
      var value = this[arguments[i]];
      if (value !== undefined){
        if (result === undefined) result = value;
        else {
          if (result.constructor != Array) result = [result];
          result.push(value)
        }
      }
      delete this[arguments[i]];
    }
    return result;
  },

  toQueryString: function() {
    return Hash.toQueryString(this);
  },

  inspect: function() {
    return '#<Hash:{' + this.map(function(pair) {
      return pair.map(Object.inspect).join(': ');
    }).join(', ') + '}>';
  },

  toJSON: function() {
    return Hash.toJSON(this);
  }
});

function $H(object) {
  if (object instanceof Hash) return object;
  return new Hash(object);
};

// Safari iterates over shadowed properties
if (function() {
  var i = 0, Test = function(value) { this.key = value };
  Test.prototype.key = 'foo';
  for (var property in new Test('bar')) i++;
  return i > 1;
}()) Hash.prototype._each = function(iterator) {
  var cache = [];
  for (var key in this) {
    var value = this[key];
    if ((value && value == Hash.prototype[key]) || cache.include(key)) continue;
    cache.push(key);
    var pair = [key, value];
    pair.key = key;
    pair.value = value;
    iterator(pair);
  }
};
ObjectRange = Class.create();
Object.extend(ObjectRange.prototype, Enumerable);
Object.extend(ObjectRange.prototype, {
  initialize: function(start, end, exclusive) {
    this.start = start;
    this.end = end;
    this.exclusive = exclusive;
  },

  _each: function(iterator) {
    var value = this.start;
    while (this.include(value)) {
      iterator(value);
      value = value.succ();
    }
  },

  include: function(value) {
    if (value < this.start)
      return false;
    if (this.exclusive)
      return value < this.end;
    return value <= this.end;
  }
});

var $R = function(start, end, exclusive) {
  return new ObjectRange(start, end, exclusive);
}

var Ajax = {
  getTransport: function() {
    return Try.these(
      function() {return new XMLHttpRequest()},
      function() {return new ActiveXObject('Msxml2.XMLHTTP')},
      function() {return new ActiveXObject('Microsoft.XMLHTTP')}
    ) || false;
  },

  activeRequestCount: 0
}

Ajax.Responders = {
  responders: [],

  _each: function(iterator) {
    this.responders._each(iterator);
  },

  register: function(responder) {
    if (!this.include(responder))
      this.responders.push(responder);
  },

  unregister: function(responder) {
    this.responders = this.responders.without(responder);
  },

  dispatch: function(callback, request, transport, json) {
    this.each(function(responder) {
      if (typeof responder[callback] == 'function') {
        try {
          responder[callback].apply(responder, [request, transport, json]);
        } catch (e) {}
      }
    });
  }
};

Object.extend(Ajax.Responders, Enumerable);

Ajax.Responders.register({
  onCreate: function() {
    Ajax.activeRequestCount++;
  },
  onComplete: function() {
    Ajax.activeRequestCount--;
  }
});

Ajax.Base = function() {};
Ajax.Base.prototype = {
  setOptions: function(options) {
    this.options = {
      method:       'post',
      asynchronous: true,
      contentType:  'application/x-www-form-urlencoded',
      encoding:     'UTF-8',
      parameters:   ''
    }
    Object.extend(this.options, options || {});

    this.options.method = this.options.method.toLowerCase();
    if (typeof this.options.parameters == 'string')
      this.options.parameters = this.options.parameters.toQueryParams();
  }
}

Ajax.Request = Class.create();
Ajax.Request.Events =
  ['Uninitialized', 'Loading', 'Loaded', 'Interactive', 'Complete'];

Ajax.Request.prototype = Object.extend(new Ajax.Base(), {
  _complete: false,

  initialize: function(url, options) {
    this.transport = Ajax.getTransport();
    this.setOptions(options);
    this.request(url);
  },

  request: function(url) {
    this.url = url;
    this.method = this.options.method;
    var params = Object.clone(this.options.parameters);

    if (!['get', 'post'].include(this.method)) {
      // simulate other verbs over post
      params['_method'] = this.method;
      this.method = 'post';
    }

    this.parameters = params;

    if (params = Hash.toQueryString(params)) {
      // when GET, append parameters to URL
      if (this.method == 'get')
        this.url += (this.url.include('?') ? '&' : '?') + params;
      else if (/Konqueror|Safari|KHTML/.test(navigator.userAgent))
        params += '&_=';
    }

    try {
      if (this.options.onCreate) this.options.onCreate(this.transport);
      Ajax.Responders.dispatch('onCreate', this, this.transport);

      this.transport.open(this.method.toUpperCase(), this.url,
        this.options.asynchronous);

      if (this.options.asynchronous)
        setTimeout(function() { this.respondToReadyState(1) }.bind(this), 10);

      this.transport.onreadystatechange = this.onStateChange.bind(this);
      this.setRequestHeaders();

      this.body = this.method == 'post' ? (this.options.postBody || params) : null;
      this.transport.send(this.body);

      /* Force Firefox to handle ready state 4 for synchronous requests */
      if (!this.options.asynchronous && this.transport.overrideMimeType)
        this.onStateChange();

    }
    catch (e) {
      this.dispatchException(e);
    }
  },

  onStateChange: function() {
    var readyState = this.transport.readyState;
    if (readyState > 1 && !((readyState == 4) && this._complete))
      this.respondToReadyState(this.transport.readyState);
  },

  setRequestHeaders: function() {
    var headers = {
      'X-Requested-With': 'XMLHttpRequest',
      'X-Prototype-Version': Prototype.Version,
      'Accept': 'text/javascript, text/html, application/xml, text/xml, */*'
    };

    if (this.method == 'post') {
      headers['Content-type'] = this.options.contentType +
        (this.options.encoding ? '; charset=' + this.options.encoding : '');

      /* Force "Connection: close" for older Mozilla browsers to work
       * around a bug where XMLHttpRequest sends an incorrect
       * Content-length header. See Mozilla Bugzilla #246651.
       */
      if (this.transport.overrideMimeType &&
          (navigator.userAgent.match(/Gecko\/(\d{4})/) || [0,2005])[1] < 2005)
            headers['Connection'] = 'close';
    }

    // user-defined headers
    if (typeof this.options.requestHeaders == 'object') {
      var extras = this.options.requestHeaders;

      if (typeof extras.push == 'function')
        for (var i = 0, length = extras.length; i < length; i += 2)
          headers[extras[i]] = extras[i+1];
      else
        $H(extras).each(function(pair) { headers[pair.key] = pair.value });
    }

    for (var name in headers)
      this.transport.setRequestHeader(name, headers[name]);
  },

  success: function() {
    return !this.transport.status
        || (this.transport.status >= 200 && this.transport.status < 300);
  },

  respondToReadyState: function(readyState) {
    var state = Ajax.Request.Events[readyState];
    var transport = this.transport, json = this.evalJSON();

    if (state == 'Complete') {
      try {
        this._complete = true;
        (this.options['on' + this.transport.status]
         || this.options['on' + (this.success() ? 'Success' : 'Failure')]
         || Prototype.emptyFunction)(transport, json);
      } catch (e) {
        this.dispatchException(e);
      }

      var contentType = this.getHeader('Content-type');
      if (contentType && contentType.strip().
        match(/^(text|application)\/(x-)?(java|ecma)script(;.*)?$/i))
          this.evalResponse();
    }

    try {
      (this.options['on' + state] || Prototype.emptyFunction)(transport, json);
      Ajax.Responders.dispatch('on' + state, this, transport, json);
    } catch (e) {
      this.dispatchException(e);
    }

    if (state == 'Complete') {
      // avoid memory leak in MSIE: clean up
      this.transport.onreadystatechange = Prototype.emptyFunction;
    }
  },

  getHeader: function(name) {
    try {
      return this.transport.getResponseHeader(name);
    } catch (e) { return null }
  },

  evalJSON: function() {
    try {
      var json = this.getHeader('X-JSON');
      return json ? json.evalJSON() : null;
    } catch (e) { return null }
  },

  evalResponse: function() {
    try {
      return eval((this.transport.responseText || '').unfilterJSON());
    } catch (e) {
      this.dispatchException(e);
    }
  },

  dispatchException: function(exception) {
    (this.options.onException || Prototype.emptyFunction)(this, exception);
    Ajax.Responders.dispatch('onException', this, exception);
  }
});

Ajax.Updater = Class.create();

Object.extend(Object.extend(Ajax.Updater.prototype, Ajax.Request.prototype), {
  initialize: function(container, url, options) {
    this.container = {
      success: (container.success || container),
      failure: (container.failure || (container.success ? null : container))
    }

    this.transport = Ajax.getTransport();
    this.setOptions(options);

    var onComplete = this.options.onComplete || Prototype.emptyFunction;
    this.options.onComplete = (function(transport, param) {
      this.updateContent();
      onComplete(transport, param);
    }).bind(this);

    this.request(url);
  },

  updateContent: function() {
    var receiver = this.container[this.success() ? 'success' : 'failure'];
    var response = this.transport.responseText;

    if (!this.options.evalScripts) response = response.stripScripts();

    if (receiver = $(receiver)) {
      if (this.options.insertion)
        new this.options.insertion(receiver, response);
      else
        receiver.update(response);
    }

    if (this.success()) {
      if (this.onComplete)
        setTimeout(this.onComplete.bind(this), 10);
    }
  }
});

Ajax.PeriodicalUpdater = Class.create();
Ajax.PeriodicalUpdater.prototype = Object.extend(new Ajax.Base(), {
  initialize: function(container, url, options) {
    this.setOptions(options);
    this.onComplete = this.options.onComplete;

    this.frequency = (this.options.frequency || 2);
    this.decay = (this.options.decay || 1);

    this.updater = {};
    this.container = container;
    this.url = url;

    this.start();
  },

  start: function() {
    this.options.onComplete = this.updateComplete.bind(this);
    this.onTimerEvent();
  },

  stop: function() {
    this.updater.options.onComplete = undefined;
    clearTimeout(this.timer);
    (this.onComplete || Prototype.emptyFunction).apply(this, arguments);
  },

  updateComplete: function(request) {
    if (this.options.decay) {
      this.decay = (request.responseText == this.lastText ?
        this.decay * this.options.decay : 1);

      this.lastText = request.responseText;
    }
    this.timer = setTimeout(this.onTimerEvent.bind(this),
      this.decay * this.frequency * 1000);
  },

  onTimerEvent: function() {
    this.updater = new Ajax.Updater(this.container, this.url, this.options);
  }
});
function $(element) {
  if (arguments.length > 1) {
    for (var i = 0, elements = [], length = arguments.length; i < length; i++)
      elements.push($(arguments[i]));
    return elements;
  }
  if (typeof element == 'string')
    element = document.getElementById(element);
  return Element.extend(element);
}

if (Prototype.BrowserFeatures.XPath) {
  document._getElementsByXPath = function(expression, parentElement) {
    var results = [];
    var query = document.evaluate(expression, $(parentElement) || document,
      null, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null);
    for (var i = 0, length = query.snapshotLength; i < length; i++)
      results.push(query.snapshotItem(i));
    return results;
  };

  document.getElementsByClassName = function(className, parentElement) {
    var q = ".//*[contains(concat(' ', @class, ' '), ' " + className + " ')]";
    return document._getElementsByXPath(q, parentElement);
  }

} else document.getElementsByClassName = function(className, parentElement) {
  var children = ($(parentElement) || document.body).getElementsByTagName('*');
  var elements = [], child;
  for (var i = 0, length = children.length; i < length; i++) {
    child = children[i];
    if (Element.hasClassName(child, className))
      elements.push(Element.extend(child));
  }
  return elements;
};

/*--------------------------------------------------------------------------*/

if (!window.Element) var Element = {};

Element.extend = function(element) {
  var F = Prototype.BrowserFeatures;
  if (!element || !element.tagName || element.nodeType == 3 ||
   element._extended || F.SpecificElementExtensions || element == window)
    return element;

  var methods = {}, tagName = element.tagName, cache = Element.extend.cache,
   T = Element.Methods.ByTag;

  // extend methods for all tags (Safari doesn't need this)
  if (!F.ElementExtensions) {
    Object.extend(methods, Element.Methods),
    Object.extend(methods, Element.Methods.Simulated);
  }

  // extend methods for specific tags
  if (T[tagName]) Object.extend(methods, T[tagName]);

  for (var property in methods) {
    var value = methods[property];
    if (typeof value == 'function' && !(property in element))
      element[property] = cache.findOrStore(value);
  }

  element._extended = Prototype.emptyFunction;
  return element;
};

Element.extend.cache = {
  findOrStore: function(value) {
    return this[value] = this[value] || function() {
      return value.apply(null, [this].concat($A(arguments)));
    }
  }
};

Element.Methods = {
  visible: function(element) {
    return $(element).style.display != 'none';
  },

  toggle: function(element) {
    element = $(element);
    Element[Element.visible(element) ? 'hide' : 'show'](element);
    return element;
  },

  hide: function(element) {
    $(element).style.display = 'none';
    return element;
  },

  show: function(element) {
    $(element).style.display = '';
    return element;
  },

  remove: function(element) {
    element = $(element);
    element.parentNode.removeChild(element);
    return element;
  },

  update: function(element, html) {
    html = typeof html == 'undefined' ? '' : html.toString();
    $(element).innerHTML = html.stripScripts();
    setTimeout(function() {html.evalScripts()}, 10);
    return element;
  },

  replace: function(element, html) {
    element = $(element);
    html = typeof html == 'undefined' ? '' : html.toString();
    if (element.outerHTML) {
      element.outerHTML = html.stripScripts();
    } else {
      var range = element.ownerDocument.createRange();
      range.selectNodeContents(element);
      element.parentNode.replaceChild(
        range.createContextualFragment(html.stripScripts()), element);
    }
    setTimeout(function() {html.evalScripts()}, 10);
    return element;
  },

  inspect: function(element) {
    element = $(element);
    var result = '<' + element.tagName.toLowerCase();
    $H({'id': 'id', 'className': 'class'}).each(function(pair) {
      var property = pair.first(), attribute = pair.last();
      var value = (element[property] || '').toString();
      if (value) result += ' ' + attribute + '=' + value.inspect(true);
    });
    return result + '>';
  },

  recursivelyCollect: function(element, property) {
    element = $(element);
    var elements = [];
    while (element = element[property])
      if (element.nodeType == 1)
        elements.push(Element.extend(element));
    return elements;
  },

  ancestors: function(element) {
    return $(element).recursivelyCollect('parentNode');
  },

  descendants: function(element) {
    return $A($(element).getElementsByTagName('*')).each(Element.extend);
  },

  firstDescendant: function(element) {
    element = $(element).firstChild;
    while (element && element.nodeType != 1) element = element.nextSibling;
    return $(element);
  },

  immediateDescendants: function(element) {
    if (!(element = $(element).firstChild)) return [];
    while (element && element.nodeType != 1) element = element.nextSibling;
    if (element) return [element].concat($(element).nextSiblings());
    return [];
  },

  previousSiblings: function(element) {
    return $(element).recursivelyCollect('previousSibling');
  },

  nextSiblings: function(element) {
    return $(element).recursivelyCollect('nextSibling');
  },

  siblings: function(element) {
    element = $(element);
    return element.previousSiblings().reverse().concat(element.nextSiblings());
  },

  match: function(element, selector) {
    if (typeof selector == 'string')
      selector = new Selector(selector);
    return selector.match($(element));
  },

  up: function(element, expression, index) {
    element = $(element);
    if (arguments.length == 1) return $(element.parentNode);
    var ancestors = element.ancestors();
    return expression ? Selector.findElement(ancestors, expression, index) :
      ancestors[index || 0];
  },

  down: function(element, expression, index) {
    element = $(element);
    if (arguments.length == 1) return element.firstDescendant();
    var descendants = element.descendants();
    return expression ? Selector.findElement(descendants, expression, index) :
      descendants[index || 0];
  },

  previous: function(element, expression, index) {
    element = $(element);
    if (arguments.length == 1) return $(Selector.handlers.previousElementSibling(element));
    var previousSiblings = element.previousSiblings();
    return expression ? Selector.findElement(previousSiblings, expression, index) :
      previousSiblings[index || 0];
  },

  next: function(element, expression, index) {
    element = $(element);
    if (arguments.length == 1) return $(Selector.handlers.nextElementSibling(element));
    var nextSiblings = element.nextSiblings();
    return expression ? Selector.findElement(nextSiblings, expression, index) :
      nextSiblings[index || 0];
  },

  getElementsBySelector: function() {
    var args = $A(arguments), element = $(args.shift());
    return Selector.findChildElements(element, args);
  },

  getElementsByClassName: function(element, className) {
    return document.getElementsByClassName(className, element);
  },

  readAttribute: function(element, name) {
    element = $(element);
    if (Prototype.Browser.IE) {
      if (!element.attributes) return null;
      var t = Element._attributeTranslations;
      if (t.values[name]) return t.values[name](element, name);
      if (t.names[name])  name = t.names[name];
      var attribute = element.attributes[name];
      return attribute ? attribute.nodeValue : null;
    }
    return element.getAttribute(name);
  },

  getHeight: function(element) {
    return $(element).getDimensions().height;
  },

  getWidth: function(element) {
    return $(element).getDimensions().width;
  },

  classNames: function(element) {
    return new Element.ClassNames(element);
  },

  hasClassName: function(element, className) {
    if (!(element = $(element))) return;
    var elementClassName = element.className;
    if (elementClassName.length == 0) return false;
    if (elementClassName == className ||
        elementClassName.match(new RegExp("(^|\\s)" + className + "(\\s|$)")))
      return true;
    return false;
  },

  addClassName: function(element, className) {
    if (!(element = $(element))) return;
    Element.classNames(element).add(className);
    return element;
  },

  removeClassName: function(element, className) {
    if (!(element = $(element))) return;
    Element.classNames(element).remove(className);
    return element;
  },

  toggleClassName: function(element, className) {
    if (!(element = $(element))) return;
    Element.classNames(element)[element.hasClassName(className) ? 'remove' : 'add'](className);
    return element;
  },

  observe: function() {
    Event.observe.apply(Event, arguments);
    return $A(arguments).first();
  },

  stopObserving: function() {
    Event.stopObserving.apply(Event, arguments);
    return $A(arguments).first();
  },

  // removes whitespace-only text node children
  cleanWhitespace: function(element) {
    element = $(element);
    var node = element.firstChild;
    while (node) {
      var nextNode = node.nextSibling;
      if (node.nodeType == 3 && !/\S/.test(node.nodeValue))
        element.removeChild(node);
      node = nextNode;
    }
    return element;
  },

  empty: function(element) {
    return $(element).innerHTML.blank();
  },

  descendantOf: function(element, ancestor) {
    element = $(element), ancestor = $(ancestor);
    while (element = element.parentNode)
      if (element == ancestor) return true;
    return false;
  },

  scrollTo: function(element) {
    element = $(element);
    var pos = Position.cumulativeOffset(element);
    window.scrollTo(pos[0], pos[1]);
    return element;
  },

  getStyle: function(element, style) {
    element = $(element);
    style = style == 'float' ? 'cssFloat' : style.camelize();
    var value = element.style[style];
    if (!value) {
      var css = document.defaultView.getComputedStyle(element, null);
      value = css ? css[style] : null;
    }
    if (style == 'opacity') return value ? parseFloat(value) : 1.0;
    return value == 'auto' ? null : value;
  },

  getOpacity: function(element) {
    return $(element).getStyle('opacity');
  },

  setStyle: function(element, styles, camelized) {
    element = $(element);
    var elementStyle = element.style;

    for (var property in styles)
      if (property == 'opacity') element.setOpacity(styles[property])
      else
        elementStyle[(property == 'float' || property == 'cssFloat') ?
          (elementStyle.styleFloat === undefined ? 'cssFloat' : 'styleFloat') :
          (camelized ? property : property.camelize())] = styles[property];

    return element;
  },

  setOpacity: function(element, value) {
    element = $(element);
    element.style.opacity = (value == 1 || value === '') ? '' :
      (value < 0.00001) ? 0 : value;
    return element;
  },

  getDimensions: function(element) {
    element = $(element);
    var display = $(element).getStyle('display');
    if (display != 'none' && display != null) // Safari bug
      return {width: element.offsetWidth, height: element.offsetHeight};

    // All *Width and *Height properties give 0 on elements with display none,
    // so enable the element temporarily
    var els = element.style;
    var originalVisibility = els.visibility;
    var originalPosition = els.position;
    var originalDisplay = els.display;
    els.visibility = 'hidden';
    els.position = 'absolute';
    els.display = 'block';
    var originalWidth = element.clientWidth;
    var originalHeight = element.clientHeight;
    els.display = originalDisplay;
    els.position = originalPosition;
    els.visibility = originalVisibility;
    return {width: originalWidth, height: originalHeight};
  },

  makePositioned: function(element) {
    element = $(element);
    var pos = Element.getStyle(element, 'position');
    if (pos == 'static' || !pos) {
      element._madePositioned = true;
      element.style.position = 'relative';
      // Opera returns the offset relative to the positioning context, when an
      // element is position relative but top and left have not been defined
      if (window.opera) {
        element.style.top = 0;
        element.style.left = 0;
      }
    }
    return element;
  },

  undoPositioned: function(element) {
    element = $(element);
    if (element._madePositioned) {
      element._madePositioned = undefined;
      element.style.position =
        element.style.top =
        element.style.left =
        element.style.bottom =
        element.style.right = '';
    }
    return element;
  },

  makeClipping: function(element) {
    element = $(element);
    if (element._overflow) return element;
    element._overflow = element.style.overflow || 'auto';
    if ((Element.getStyle(element, 'overflow') || 'visible') != 'hidden')
      element.style.overflow = 'hidden';
    return element;
  },

  undoClipping: function(element) {
    element = $(element);
    if (!element._overflow) return element;
    element.style.overflow = element._overflow == 'auto' ? '' : element._overflow;
    element._overflow = null;
    return element;
  }
};

Object.extend(Element.Methods, {
  childOf: Element.Methods.descendantOf,
  childElements: Element.Methods.immediateDescendants
});

if (Prototype.Browser.Opera) {
  Element.Methods._getStyle = Element.Methods.getStyle;
  Element.Methods.getStyle = function(element, style) {
    switch(style) {
      case 'left':
      case 'top':
      case 'right':
      case 'bottom':
        if (Element._getStyle(element, 'position') == 'static') return null;
      default: return Element._getStyle(element, style);
    }
  };
}
else if (Prototype.Browser.IE) {
  Element.Methods.getStyle = function(element, style) {
    element = $(element);
    style = (style == 'float' || style == 'cssFloat') ? 'styleFloat' : style.camelize();
    var value = element.style[style];
    if (!value && element.currentStyle) value = element.currentStyle[style];

    if (style == 'opacity') {
      if (value = (element.getStyle('filter') || '').match(/alpha\(opacity=(.*)\)/))
        if (value[1]) return parseFloat(value[1]) / 100;
      return 1.0;
    }

    if (value == 'auto') {
      if ((style == 'width' || style == 'height') && (element.getStyle('display') != 'none'))
        return element['offset'+style.capitalize()] + 'px';
      return null;
    }
    return value;
  };

  Element.Methods.setOpacity = function(element, value) {
    element = $(element);
    var filter = element.getStyle('filter'), style = element.style;
    if (value == 1 || value === '') {
      style.filter = filter.replace(/alpha\([^\)]*\)/gi,'');
      return element;
    } else if (value < 0.00001) value = 0;
    style.filter = filter.replace(/alpha\([^\)]*\)/gi, '') +
      'alpha(opacity=' + (value * 100) + ')';
    return element;
  };

  // IE is missing .innerHTML support for TABLE-related elements
  Element.Methods.update = function(element, html) {
    element = $(element);
    html = typeof html == 'undefined' ? '' : html.toString();
    var tagName = element.tagName.toUpperCase();
    if (['THEAD','TBODY','TR','TD'].include(tagName)) {
      var div = document.createElement('div');
      switch (tagName) {
        case 'THEAD':
        case 'TBODY':
          div.innerHTML = '<table><tbody>' +  html.stripScripts() + '</tbody></table>';
          depth = 2;
          break;
        case 'TR':
          div.innerHTML = '<table><tbody><tr>' +  html.stripScripts() + '</tr></tbody></table>';
          depth = 3;
          break;
        case 'TD':
          div.innerHTML = '<table><tbody><tr><td>' +  html.stripScripts() + '</td></tr></tbody></table>';
          depth = 4;
      }
      $A(element.childNodes).each(function(node) { element.removeChild(node) });
      depth.times(function() { div = div.firstChild });
      $A(div.childNodes).each(function(node) { element.appendChild(node) });
    } else {
      element.innerHTML = html.stripScripts();
    }
    setTimeout(function() { html.evalScripts() }, 10);
    return element;
  }
}
else if (Prototype.Browser.Gecko) {
  Element.Methods.setOpacity = function(element, value) {
    element = $(element);
    element.style.opacity = (value == 1) ? 0.999999 :
      (value === '') ? '' : (value < 0.00001) ? 0 : value;
    return element;
  };
}

Element._attributeTranslations = {
  names: {
    colspan:   "colSpan",
    rowspan:   "rowSpan",
    valign:    "vAlign",
    datetime:  "dateTime",
    accesskey: "accessKey",
    tabindex:  "tabIndex",
    enctype:   "encType",
    maxlength: "maxLength",
    readonly:  "readOnly",
    longdesc:  "longDesc"
  },
  values: {
    _getAttr: function(element, attribute) {
      return element.getAttribute(attribute, 2);
    },
    _flag: function(element, attribute) {
      return $(element).hasAttribute(attribute) ? attribute : null;
    },
    style: function(element) {
      return element.style.cssText.toLowerCase();
    },
    title: function(element) {
      var node = element.getAttributeNode('title');
      return node.specified ? node.nodeValue : null;
    }
  }
};

(function() {
  Object.extend(this, {
    href: this._getAttr,
    src:  this._getAttr,
    type: this._getAttr,
    disabled: this._flag,
    checked:  this._flag,
    readonly: this._flag,
    multiple: this._flag
  });
}).call(Element._attributeTranslations.values);

Element.Methods.Simulated = {
  hasAttribute: function(element, attribute) {
    var t = Element._attributeTranslations, node;
    attribute = t.names[attribute] || attribute;
    node = $(element).getAttributeNode(attribute);
    return node && node.specified;
  }
};

Element.Methods.ByTag = {};

Object.extend(Element, Element.Methods);

if (!Prototype.BrowserFeatures.ElementExtensions &&
 document.createElement('div').__proto__) {
  window.HTMLElement = {};
  window.HTMLElement.prototype = document.createElement('div').__proto__;
  Prototype.BrowserFeatures.ElementExtensions = true;
}

Element.hasAttribute = function(element, attribute) {
  if (element.hasAttribute) return element.hasAttribute(attribute);
  return Element.Methods.Simulated.hasAttribute(element, attribute);
};

Element.addMethods = function(methods) {
  var F = Prototype.BrowserFeatures, T = Element.Methods.ByTag;

  if (!methods) {
    Object.extend(Form, Form.Methods);
    Object.extend(Form.Element, Form.Element.Methods);
    Object.extend(Element.Methods.ByTag, {
      "FORM":     Object.clone(Form.Methods),
      "INPUT":    Object.clone(Form.Element.Methods),
      "SELECT":   Object.clone(Form.Element.Methods),
      "TEXTAREA": Object.clone(Form.Element.Methods)
    });
  }

  if (arguments.length == 2) {
    var tagName = methods;
    methods = arguments[1];
  }

  if (!tagName) Object.extend(Element.Methods, methods || {});
  else {
    if (tagName.constructor == Array) tagName.each(extend);
    else extend(tagName);
  }

  function extend(tagName) {
    tagName = tagName.toUpperCase();
    if (!Element.Methods.ByTag[tagName])
      Element.Methods.ByTag[tagName] = {};
    Object.extend(Element.Methods.ByTag[tagName], methods);
  }

  function copy(methods, destination, onlyIfAbsent) {
    onlyIfAbsent = onlyIfAbsent || false;
    var cache = Element.extend.cache;
    for (var property in methods) {
      var value = methods[property];
      if (!onlyIfAbsent || !(property in destination))
        destination[property] = cache.findOrStore(value);
    }
  }

  function findDOMClass(tagName) {
    var klass;
    var trans = {
      "OPTGROUP": "OptGroup", "TEXTAREA": "TextArea", "P": "Paragraph",
      "FIELDSET": "FieldSet", "UL": "UList", "OL": "OList", "DL": "DList",
      "DIR": "Directory", "H1": "Heading", "H2": "Heading", "H3": "Heading",
      "H4": "Heading", "H5": "Heading", "H6": "Heading", "Q": "Quote",
      "INS": "Mod", "DEL": "Mod", "A": "Anchor", "IMG": "Image", "CAPTION":
      "TableCaption", "COL": "TableCol", "COLGROUP": "TableCol", "THEAD":
      "TableSection", "TFOOT": "TableSection", "TBODY": "TableSection", "TR":
      "TableRow", "TH": "TableCell", "TD": "TableCell", "FRAMESET":
      "FrameSet", "IFRAME": "IFrame"
    };
    if (trans[tagName]) klass = 'HTML' + trans[tagName] + 'Element';
    if (window[klass]) return window[klass];
    klass = 'HTML' + tagName + 'Element';
    if (window[klass]) return window[klass];
    klass = 'HTML' + tagName.capitalize() + 'Element';
    if (window[klass]) return window[klass];

    window[klass] = {};
    window[klass].prototype = document.createElement(tagName).__proto__;
    return window[klass];
  }

  if (F.ElementExtensions) {
    copy(Element.Methods, HTMLElement.prototype);
    copy(Element.Methods.Simulated, HTMLElement.prototype, true);
  }

  if (F.SpecificElementExtensions) {
    for (var tag in Element.Methods.ByTag) {
      var klass = findDOMClass(tag);
      if (typeof klass == "undefined") continue;
      copy(T[tag], klass.prototype);
    }
  }

  Object.extend(Element, Element.Methods);
  delete Element.ByTag;
};

var Toggle = { display: Element.toggle };

/*--------------------------------------------------------------------------*/

Abstract.Insertion = function(adjacency) {
  this.adjacency = adjacency;
}

Abstract.Insertion.prototype = {
  initialize: function(element, content) {
    this.element = $(element);
    this.content = content.stripScripts();

    if (this.adjacency && this.element.insertAdjacentHTML) {
      try {
        this.element.insertAdjacentHTML(this.adjacency, this.content);
      } catch (e) {
        var tagName = this.element.tagName.toUpperCase();
        if (['TBODY', 'TR'].include(tagName)) {
          this.insertContent(this.contentFromAnonymousTable());
        } else {
          throw e;
        }
      }
    } else {
      this.range = this.element.ownerDocument.createRange();
      if (this.initializeRange) this.initializeRange();
      this.insertContent([this.range.createContextualFragment(this.content)]);
    }

    setTimeout(function() {content.evalScripts()}, 10);
  },

  contentFromAnonymousTable: function() {
    var div = document.createElement('div');
    div.innerHTML = '<table><tbody>' + this.content + '</tbody></table>';
    return $A(div.childNodes[0].childNodes[0].childNodes);
  }
}

var Insertion = new Object();

Insertion.Before = Class.create();
Insertion.Before.prototype = Object.extend(new Abstract.Insertion('beforeBegin'), {
  initializeRange: function() {
    this.range.setStartBefore(this.element);
  },

  insertContent: function(fragments) {
    fragments.each((function(fragment) {
      this.element.parentNode.insertBefore(fragment, this.element);
    }).bind(this));
  }
});

Insertion.Top = Class.create();
Insertion.Top.prototype = Object.extend(new Abstract.Insertion('afterBegin'), {
  initializeRange: function() {
    this.range.selectNodeContents(this.element);
    this.range.collapse(true);
  },

  insertContent: function(fragments) {
    fragments.reverse(false).each((function(fragment) {
      this.element.insertBefore(fragment, this.element.firstChild);
    }).bind(this));
  }
});

Insertion.Bottom = Class.create();
Insertion.Bottom.prototype = Object.extend(new Abstract.Insertion('beforeEnd'), {
  initializeRange: function() {
    this.range.selectNodeContents(this.element);
    this.range.collapse(this.element);
  },

  insertContent: function(fragments) {
    fragments.each((function(fragment) {
      this.element.appendChild(fragment);
    }).bind(this));
  }
});

Insertion.After = Class.create();
Insertion.After.prototype = Object.extend(new Abstract.Insertion('afterEnd'), {
  initializeRange: function() {
    this.range.setStartAfter(this.element);
  },

  insertContent: function(fragments) {
    fragments.each((function(fragment) {
      this.element.parentNode.insertBefore(fragment,
        this.element.nextSibling);
    }).bind(this));
  }
});

/*--------------------------------------------------------------------------*/

Element.ClassNames = Class.create();
Element.ClassNames.prototype = {
  initialize: function(element) {
    this.element = $(element);
  },

  _each: function(iterator) {
    this.element.className.split(/\s+/).select(function(name) {
      return name.length > 0;
    })._each(iterator);
  },

  set: function(className) {
    this.element.className = className;
  },

  add: function(classNameToAdd) {
    if (this.include(classNameToAdd)) return;
    this.set($A(this).concat(classNameToAdd).join(' '));
  },

  remove: function(classNameToRemove) {
    if (!this.include(classNameToRemove)) return;
    this.set($A(this).without(classNameToRemove).join(' '));
  },

  toString: function() {
    return $A(this).join(' ');
  }
};

Object.extend(Element.ClassNames.prototype, Enumerable);
/* Portions of the Selector class are derived from Jack Slocum???s DomQuery,
 * part of YUI-Ext version 0.40, distributed under the terms of an MIT-style
 * license.  Please see http://www.yui-ext.com/ for more information. */

var Selector = Class.create();

Selector.prototype = {
  initialize: function(expression) {
    this.expression = expression.strip();
    this.compileMatcher();
  },

  compileMatcher: function() {
    // Selectors with namespaced attributes can't use the XPath version
    if (Prototype.BrowserFeatures.XPath && !(/\[[\w-]*?:/).test(this.expression))
      return this.compileXPathMatcher();

    var e = this.expression, ps = Selector.patterns, h = Selector.handlers,
        c = Selector.criteria, le, p, m;

    if (Selector._cache[e]) {
      this.matcher = Selector._cache[e]; return;
    }
    this.matcher = ["this.matcher = function(root) {",
                    "var r = root, h = Selector.handlers, c = false, n;"];

    while (e && le != e && (/\S/).test(e)) {
      le = e;
      for (var i in ps) {
        p = ps[i];
        if (m = e.match(p)) {
          this.matcher.push(typeof c[i] == 'function' ? c[i](m) :
    	      new Template(c[i]).evaluate(m));
          e = e.replace(m[0], '');
          break;
        }
      }
    }

    this.matcher.push("return h.unique(n);\n}");
    eval(this.matcher.join('\n'));
    Selector._cache[this.expression] = this.matcher;
  },

  compileXPathMatcher: function() {
    var e = this.expression, ps = Selector.patterns,
        x = Selector.xpath, le,  m;

    if (Selector._cache[e]) {
      this.xpath = Selector._cache[e]; return;
    }

    this.matcher = ['.//*'];
    while (e && le != e && (/\S/).test(e)) {
      le = e;
      for (var i in ps) {
        if (m = e.match(ps[i])) {
          this.matcher.push(typeof x[i] == 'function' ? x[i](m) :
            new Template(x[i]).evaluate(m));
          e = e.replace(m[0], '');
          break;
        }
      }
    }

    this.xpath = this.matcher.join('');
    Selector._cache[this.expression] = this.xpath;
  },

  findElements: function(root) {
    root = root || document;
    if (this.xpath) return document._getElementsByXPath(this.xpath, root);
    return this.matcher(root);
  },

  match: function(element) {
    return this.findElements(document).include(element);
  },

  toString: function() {
    return this.expression;
  },

  inspect: function() {
    return "#<Selector:" + this.expression.inspect() + ">";
  }
};

Object.extend(Selector, {
  _cache: {},

  xpath: {
    descendant:   "//*",
    child:        "/*",
    adjacent:     "/following-sibling::*[1]",
    laterSibling: '/following-sibling::*',
    tagName:      function(m) {
      if (m[1] == '*') return '';
      return "[local-name()='" + m[1].toLowerCase() +
             "' or local-name()='" + m[1].toUpperCase() + "']";
    },
    className:    "[contains(concat(' ', @class, ' '), ' #{1} ')]",
    id:           "[@id='#{1}']",
    attrPresence: "[@#{1}]",
    attr: function(m) {
      m[3] = m[5] || m[6];
      return new Template(Selector.xpath.operators[m[2]]).evaluate(m);
    },
    pseudo: function(m) {
      var h = Selector.xpath.pseudos[m[1]];
      if (!h) return '';
      if (typeof h === 'function') return h(m);
      return new Template(Selector.xpath.pseudos[m[1]]).evaluate(m);
    },
    operators: {
      '=':  "[@#{1}='#{3}']",
      '!=': "[@#{1}!='#{3}']",
      '^=': "[starts-with(@#{1}, '#{3}')]",
      '$=': "[substring(@#{1}, (string-length(@#{1}) - string-length('#{3}') + 1))='#{3}']",
      '*=': "[contains(@#{1}, '#{3}')]",
      '~=': "[contains(concat(' ', @#{1}, ' '), ' #{3} ')]",
      '|=': "[contains(concat('-', @#{1}, '-'), '-#{3}-')]"
    },
    pseudos: {
      'first-child': '[not(preceding-sibling::*)]',
      'last-child':  '[not(following-sibling::*)]',
      'only-child':  '[not(preceding-sibling::* or following-sibling::*)]',
      'empty':       "[count(*) = 0 and (count(text()) = 0 or translate(text(), ' \t\r\n', '') = '')]",
      'checked':     "[@checked]",
      'disabled':    "[@disabled]",
      'enabled':     "[not(@disabled)]",
      'not': function(m) {
        var e = m[6], p = Selector.patterns,
            x = Selector.xpath, le, m, v;

        var exclusion = [];
        while (e && le != e && (/\S/).test(e)) {
          le = e;
          for (var i in p) {
            if (m = e.match(p[i])) {
              v = typeof x[i] == 'function' ? x[i](m) : new Template(x[i]).evaluate(m);
              exclusion.push("(" + v.substring(1, v.length - 1) + ")");
              e = e.replace(m[0], '');
              break;
            }
          }
        }
        return "[not(" + exclusion.join(" and ") + ")]";
      },
      'nth-child':      function(m) {
        return Selector.xpath.pseudos.nth("(count(./preceding-sibling::*) + 1) ", m);
      },
      'nth-last-child': function(m) {
        return Selector.xpath.pseudos.nth("(count(./following-sibling::*) + 1) ", m);
      },
      'nth-of-type':    function(m) {
        return Selector.xpath.pseudos.nth("position() ", m);
      },
      'nth-last-of-type': function(m) {
        return Selector.xpath.pseudos.nth("(last() + 1 - position()) ", m);
      },
      'first-of-type':  function(m) {
        m[6] = "1"; return Selector.xpath.pseudos['nth-of-type'](m);
      },
      'last-of-type':   function(m) {
        m[6] = "1"; return Selector.xpath.pseudos['nth-last-of-type'](m);
      },
      'only-of-type':   function(m) {
        var p = Selector.xpath.pseudos; return p['first-of-type'](m) + p['last-of-type'](m);
      },
      nth: function(fragment, m) {
        var mm, formula = m[6], predicate;
        if (formula == 'even') formula = '2n+0';
        if (formula == 'odd')  formula = '2n+1';
        if (mm = formula.match(/^(\d+)$/)) // digit only
          return '[' + fragment + "= " + mm[1] + ']';
        if (mm = formula.match(/^(-?\d*)?n(([+-])(\d+))?/)) { // an+b
          if (mm[1] == "-") mm[1] = -1;
          var a = mm[1] ? Number(mm[1]) : 1;
          var b = mm[2] ? Number(mm[2]) : 0;
          predicate = "[((#{fragment} - #{b}) mod #{a} = 0) and " +
          "((#{fragment} - #{b}) div #{a} >= 0)]";
          return new Template(predicate).evaluate({
            fragment: fragment, a: a, b: b });
        }
      }
    }
  },

  criteria: {
    tagName:      'n = h.tagName(n, r, "#{1}", c);   c = false;',
    className:    'n = h.className(n, r, "#{1}", c); c = false;',
    id:           'n = h.id(n, r, "#{1}", c);        c = false;',
    attrPresence: 'n = h.attrPresence(n, r, "#{1}"); c = false;',
    attr: function(m) {
      m[3] = (m[5] || m[6]);
      return new Template('n = h.attr(n, r, "#{1}", "#{3}", "#{2}"); c = false;').evaluate(m);
    },
    pseudo:       function(m) {
      if (m[6]) m[6] = m[6].replace(/"/g, '\\"');
      return new Template('n = h.pseudo(n, "#{1}", "#{6}", r, c); c = false;').evaluate(m);
    },
    descendant:   'c = "descendant";',
    child:        'c = "child";',
    adjacent:     'c = "adjacent";',
    laterSibling: 'c = "laterSibling";'
  },

  patterns: {
    // combinators must be listed first
    // (and descendant needs to be last combinator)
    laterSibling: /^\s*~\s*/,
    child:        /^\s*>\s*/,
    adjacent:     /^\s*\+\s*/,
    descendant:   /^\s/,

    // selectors follow
    tagName:      /^\s*(\*|[\w\-]+)(\b|$)?/,
    id:           /^#([\w\-\*]+)(\b|$)/,
    className:    /^\.([\w\-\*]+)(\b|$)/,
    pseudo:       /^:((first|last|nth|nth-last|only)(-child|-of-type)|empty|checked|(en|dis)abled|not)(\((.*?)\))?(\b|$|\s|(?=:))/,
    attrPresence: /^\[([\w]+)\]/,
    attr:         /\[((?:[\w-]*:)?[\w-]+)\s*(?:([!^$*~|]?=)\s*((['"])([^\]]*?)\4|([^'"][^\]]*?)))?\]/
  },

  handlers: {
    // UTILITY FUNCTIONS
    // joins two collections
    concat: function(a, b) {
      for (var i = 0, node; node = b[i]; i++)
        a.push(node);
      return a;
    },

    // marks an array of nodes for counting
    mark: function(nodes) {
      for (var i = 0, node; node = nodes[i]; i++)
        node._counted = true;
      return nodes;
    },

    unmark: function(nodes) {
      for (var i = 0, node; node = nodes[i]; i++)
        node._counted = undefined;
      return nodes;
    },

    // mark each child node with its position (for nth calls)
    // "ofType" flag indicates whether we're indexing for nth-of-type
    // rather than nth-child
    index: function(parentNode, reverse, ofType) {
      parentNode._counted = true;
      if (reverse) {
        for (var nodes = parentNode.childNodes, i = nodes.length - 1, j = 1; i >= 0; i--) {
          node = nodes[i];
          if (node.nodeType == 1 && (!ofType || node._counted)) node.nodeIndex = j++;
        }
      } else {
        for (var i = 0, j = 1, nodes = parentNode.childNodes; node = nodes[i]; i++)
          if (node.nodeType == 1 && (!ofType || node._counted)) node.nodeIndex = j++;
      }
    },

    // filters out duplicates and extends all nodes
    unique: function(nodes) {
      if (nodes.length == 0) return nodes;
      var results = [], n;
      for (var i = 0, l = nodes.length; i < l; i++)
        if (!(n = nodes[i])._counted) {
          n._counted = true;
          results.push(Element.extend(n));
        }
      return Selector.handlers.unmark(results);
    },

    // COMBINATOR FUNCTIONS
    descendant: function(nodes) {
      var h = Selector.handlers;
      for (var i = 0, results = [], node; node = nodes[i]; i++)
        h.concat(results, node.getElementsByTagName('*'));
      return results;
    },

    child: function(nodes) {
      var h = Selector.handlers;
      for (var i = 0, results = [], node; node = nodes[i]; i++) {
        for (var j = 0, children = [], child; child = node.childNodes[j]; j++)
          if (child.nodeType == 1 && child.tagName != '!') results.push(child);
      }
      return results;
    },

    adjacent: function(nodes) {
      for (var i = 0, results = [], node; node = nodes[i]; i++) {
        var next = this.nextElementSibling(node);
        if (next) results.push(next);
      }
      return results;
    },

    laterSibling: function(nodes) {
      var h = Selector.handlers;
      for (var i = 0, results = [], node; node = nodes[i]; i++)
        h.concat(results, Element.nextSiblings(node));
      return results;
    },

    nextElementSibling: function(node) {
      while (node = node.nextSibling)
	      if (node.nodeType == 1) return node;
      return null;
    },

    previousElementSibling: function(node) {
      while (node = node.previousSibling)
        if (node.nodeType == 1) return node;
      return null;
    },

    // TOKEN FUNCTIONS
    tagName: function(nodes, root, tagName, combinator) {
      tagName = tagName.toUpperCase();
      var results = [], h = Selector.handlers;
      if (nodes) {
        if (combinator) {
          // fastlane for ordinary descendant combinators
          if (combinator == "descendant") {
            for (var i = 0, node; node = nodes[i]; i++)
              h.concat(results, node.getElementsByTagName(tagName));
            return results;
          } else nodes = this[combinator](nodes);
          if (tagName == "*") return nodes;
        }
        for (var i = 0, node; node = nodes[i]; i++)
          if (node.tagName.toUpperCase() == tagName) results.push(node);
        return results;
      } else return root.getElementsByTagName(tagName);
    },

    id: function(nodes, root, id, combinator) {
      var targetNode = $(id), h = Selector.handlers;
      if (!nodes && root == document) return targetNode ? [targetNode] : [];
      if (nodes) {
        if (combinator) {
          if (combinator == 'child') {
            for (var i = 0, node; node = nodes[i]; i++)
              if (targetNode.parentNode == node) return [targetNode];
          } else if (combinator == 'descendant') {
            for (var i = 0, node; node = nodes[i]; i++)
              if (Element.descendantOf(targetNode, node)) return [targetNode];
          } else if (combinator == 'adjacent') {
            for (var i = 0, node; node = nodes[i]; i++)
              if (Selector.handlers.previousElementSibling(targetNode) == node)
                return [targetNode];
          } else nodes = h[combinator](nodes);
        }
        for (var i = 0, node; node = nodes[i]; i++)
          if (node == targetNode) return [targetNode];
        return [];
      }
      return (targetNode && Element.descendantOf(targetNode, root)) ? [targetNode] : [];
    },

    className: function(nodes, root, className, combinator) {
      if (nodes && combinator) nodes = this[combinator](nodes);
      return Selector.handlers.byClassName(nodes, root, className);
    },

    byClassName: function(nodes, root, className) {
      if (!nodes) nodes = Selector.handlers.descendant([root]);
      var needle = ' ' + className + ' ';
      for (var i = 0, results = [], node, nodeClassName; node = nodes[i]; i++) {
        nodeClassName = node.className;
        if (nodeClassName.length == 0) continue;
        if (nodeClassName == className || (' ' + nodeClassName + ' ').include(needle))
          results.push(node);
      }
      return results;
    },

    attrPresence: function(nodes, root, attr) {
      var results = [];
      for (var i = 0, node; node = nodes[i]; i++)
        if (Element.hasAttribute(node, attr)) results.push(node);
      return results;
    },

    attr: function(nodes, root, attr, value, operator) {
      if (!nodes) nodes = root.getElementsByTagName("*");
      var handler = Selector.operators[operator], results = [];
      for (var i = 0, node; node = nodes[i]; i++) {
        var nodeValue = Element.readAttribute(node, attr);
        if (nodeValue === null) continue;
        if (handler(nodeValue, value)) results.push(node);
      }
      return results;
    },

    pseudo: function(nodes, name, value, root, combinator) {
      if (nodes && combinator) nodes = this[combinator](nodes);
      if (!nodes) nodes = root.getElementsByTagName("*");
      return Selector.pseudos[name](nodes, value, root);
    }
  },

  pseudos: {
    'first-child': function(nodes, value, root) {
      for (var i = 0, results = [], node; node = nodes[i]; i++) {
        if (Selector.handlers.previousElementSibling(node)) continue;
          results.push(node);
      }
      return results;
    },
    'last-child': function(nodes, value, root) {
      for (var i = 0, results = [], node; node = nodes[i]; i++) {
        if (Selector.handlers.nextElementSibling(node)) continue;
          results.push(node);
      }
      return results;
    },
    'only-child': function(nodes, value, root) {
      var h = Selector.handlers;
      for (var i = 0, results = [], node; node = nodes[i]; i++)
        if (!h.previousElementSibling(node) && !h.nextElementSibling(node))
          results.push(node);
      return results;
    },
    'nth-child':        function(nodes, formula, root) {
      return Selector.pseudos.nth(nodes, formula, root);
    },
    'nth-last-child':   function(nodes, formula, root) {
      return Selector.pseudos.nth(nodes, formula, root, true);
    },
    'nth-of-type':      function(nodes, formula, root) {
      return Selector.pseudos.nth(nodes, formula, root, false, true);
    },
    'nth-last-of-type': function(nodes, formula, root) {
      return Selector.pseudos.nth(nodes, formula, root, true, true);
    },
    'first-of-type':    function(nodes, formula, root) {
      return Selector.pseudos.nth(nodes, "1", root, false, true);
    },
    'last-of-type':     function(nodes, formula, root) {
      return Selector.pseudos.nth(nodes, "1", root, true, true);
    },
    'only-of-type':     function(nodes, formula, root) {
      var p = Selector.pseudos;
      return p['last-of-type'](p['first-of-type'](nodes, formula, root), formula, root);
    },

    // handles the an+b logic
    getIndices: function(a, b, total) {
      if (a == 0) return b > 0 ? [b] : [];
      return $R(1, total).inject([], function(memo, i) {
        if (0 == (i - b) % a && (i - b) / a >= 0) memo.push(i);
        return memo;
      });
    },

    // handles nth(-last)-child, nth(-last)-of-type, and (first|last)-of-type
    nth: function(nodes, formula, root, reverse, ofType) {
      if (nodes.length == 0) return [];
      if (formula == 'even') formula = '2n+0';
      if (formula == 'odd')  formula = '2n+1';
      var h = Selector.handlers, results = [], indexed = [], m;
      h.mark(nodes);
      for (var i = 0, node; node = nodes[i]; i++) {
        if (!node.parentNode._counted) {
          h.index(node.parentNode, reverse, ofType);
          indexed.push(node.parentNode);
        }
      }
      if (formula.match(/^\d+$/)) { // just a number
        formula = Number(formula);
        for (var i = 0, node; node = nodes[i]; i++)
          if (node.nodeIndex == formula) results.push(node);
      } else if (m = formula.match(/^(-?\d*)?n(([+-])(\d+))?/)) { // an+b
        if (m[1] == "-") m[1] = -1;
        var a = m[1] ? Number(m[1]) : 1;
        var b = m[2] ? Number(m[2]) : 0;
        var indices = Selector.pseudos.getIndices(a, b, nodes.length);
        for (var i = 0, node, l = indices.length; node = nodes[i]; i++) {
          for (var j = 0; j < l; j++)
            if (node.nodeIndex == indices[j]) results.push(node);
        }
      }
      h.unmark(nodes);
      h.unmark(indexed);
      return results;
    },

    'empty': function(nodes, value, root) {
      for (var i = 0, results = [], node; node = nodes[i]; i++) {
        // IE treats comments as element nodes
        if (node.tagName == '!' || (node.firstChild && !node.innerHTML.match(/^\s*$/))) continue;
        results.push(node);
      }
      return results;
    },

    'not': function(nodes, selector, root) {
      var h = Selector.handlers, selectorType, m;
      var exclusions = new Selector(selector).findElements(root);
      h.mark(exclusions);
      for (var i = 0, results = [], node; node = nodes[i]; i++)
        if (!node._counted) results.push(node);
      h.unmark(exclusions);
      return results;
    },

    'enabled': function(nodes, value, root) {
      for (var i = 0, results = [], node; node = nodes[i]; i++)
        if (!node.disabled) results.push(node);
      return results;
    },

    'disabled': function(nodes, value, root) {
      for (var i = 0, results = [], node; node = nodes[i]; i++)
        if (node.disabled) results.push(node);
      return results;
    },

    'checked': function(nodes, value, root) {
      for (var i = 0, results = [], node; node = nodes[i]; i++)
        if (node.checked) results.push(node);
      return results;
    }
  },

  operators: {
    '=':  function(nv, v) { return nv == v; },
    '!=': function(nv, v) { return nv != v; },
    '^=': function(nv, v) { return nv.startsWith(v); },
    '$=': function(nv, v) { return nv.endsWith(v); },
    '*=': function(nv, v) { return nv.include(v); },
    '~=': function(nv, v) { return (' ' + nv + ' ').include(' ' + v + ' '); },
    '|=': function(nv, v) { return ('-' + nv.toUpperCase() + '-').include('-' + v.toUpperCase() + '-'); }
  },

  matchElements: function(elements, expression) {
    var matches = new Selector(expression).findElements(), h = Selector.handlers;
    h.mark(matches);
    for (var i = 0, results = [], element; element = elements[i]; i++)
      if (element._counted) results.push(element);
    h.unmark(matches);
    return results;
  },

  findElement: function(elements, expression, index) {
    if (typeof expression == 'number') {
      index = expression; expression = false;
    }
    return Selector.matchElements(elements, expression || '*')[index || 0];
  },

  findChildElements: function(element, expressions) {
    var exprs = expressions.join(','), expressions = [];
    exprs.scan(/(([\w#:.~>+()\s-]+|\*|\[.*?\])+)\s*(,|$)/, function(m) {
      expressions.push(m[1].strip());
    });
    var results = [], h = Selector.handlers;
    for (var i = 0, l = expressions.length, selector; i < l; i++) {
      selector = new Selector(expressions[i].strip());
      h.concat(results, selector.findElements(element));
    }
    return (l > 1) ? h.unique(results) : results;
  }
});

function $$() {
  return Selector.findChildElements(document, $A(arguments));
}
var Form = {
  reset: function(form) {
    $(form).reset();
    return form;
  },

  serializeElements: function(elements, getHash) {
    var data = elements.inject({}, function(result, element) {
      if (!element.disabled && element.name) {
        var key = element.name, value = $(element).getValue();
        if (value != null) {
         	if (key in result) {
            if (result[key].constructor != Array) result[key] = [result[key]];
            result[key].push(value);
          }
          else result[key] = value;
        }
      }
      return result;
    });

    return getHash ? data : Hash.toQueryString(data);
  }
};

Form.Methods = {
  serialize: function(form, getHash) {
    return Form.serializeElements(Form.getElements(form), getHash);
  },

  getElements: function(form) {
    return $A($(form).getElementsByTagName('*')).inject([],
      function(elements, child) {
        if (Form.Element.Serializers[child.tagName.toLowerCase()])
          elements.push(Element.extend(child));
        return elements;
      }
    );
  },

  getInputs: function(form, typeName, name) {
    form = $(form);
    var inputs = form.getElementsByTagName('input');

    if (!typeName && !name) return $A(inputs).map(Element.extend);

    for (var i = 0, matchingInputs = [], length = inputs.length; i < length; i++) {
      var input = inputs[i];
      if ((typeName && input.type != typeName) || (name && input.name != name))
        continue;
      matchingInputs.push(Element.extend(input));
    }

    return matchingInputs;
  },

  disable: function(form) {
    form = $(form);
    Form.getElements(form).invoke('disable');
    return form;
  },

  enable: function(form) {
    form = $(form);
    Form.getElements(form).invoke('enable');
    return form;
  },

  findFirstElement: function(form) {
    return $(form).getElements().find(function(element) {
      return element.type != 'hidden' && !element.disabled &&
        ['input', 'select', 'textarea'].include(element.tagName.toLowerCase());
    });
  },

  focusFirstElement: function(form) {
    form = $(form);
    form.findFirstElement().activate();
    return form;
  },

  request: function(form, options) {
    form = $(form), options = Object.clone(options || {});

    var params = options.parameters;
    options.parameters = form.serialize(true);

    if (params) {
      if (typeof params == 'string') params = params.toQueryParams();
      Object.extend(options.parameters, params);
    }

    if (form.hasAttribute('method') && !options.method)
      options.method = form.method;

    return new Ajax.Request(form.readAttribute('action'), options);
  }
}

/*--------------------------------------------------------------------------*/

Form.Element = {
  focus: function(element) {
    $(element).focus();
    return element;
  },

  select: function(element) {
    $(element).select();
    return element;
  }
}

Form.Element.Methods = {
  serialize: function(element) {
    element = $(element);
    if (!element.disabled && element.name) {
      var value = element.getValue();
      if (value != undefined) {
        var pair = {};
        pair[element.name] = value;
        return Hash.toQueryString(pair);
      }
    }
    return '';
  },

  getValue: function(element) {
    element = $(element);
    var method = element.tagName.toLowerCase();
    return Form.Element.Serializers[method](element);
  },

  clear: function(element) {
    $(element).value = '';
    return element;
  },

  present: function(element) {
    return $(element).value != '';
  },

  activate: function(element) {
    element = $(element);
    try {
      element.focus();
      if (element.select && (element.tagName.toLowerCase() != 'input' ||
        !['button', 'reset', 'submit'].include(element.type)))
        element.select();
    } catch (e) {}
    return element;
  },

  disable: function(element) {
    element = $(element);
    element.blur();
    element.disabled = true;
    return element;
  },

  enable: function(element) {
    element = $(element);
    element.disabled = false;
    return element;
  }
}

/*--------------------------------------------------------------------------*/

var Field = Form.Element;
var $F = Form.Element.Methods.getValue;

/*--------------------------------------------------------------------------*/

Form.Element.Serializers = {
  input: function(element) {
    switch (element.type.toLowerCase()) {
      case 'checkbox':
      case 'radio':
        return Form.Element.Serializers.inputSelector(element);
      default:
        return Form.Element.Serializers.textarea(element);
    }
  },

  inputSelector: function(element) {
    return element.checked ? element.value : null;
  },

  textarea: function(element) {
    return element.value;
  },

  select: function(element) {
    return this[element.type == 'select-one' ?
      'selectOne' : 'selectMany'](element);
  },

  selectOne: function(element) {
    var index = element.selectedIndex;
    return index >= 0 ? this.optionValue(element.options[index]) : null;
  },

  selectMany: function(element) {
    var values, length = element.length;
    if (!length) return null;

    for (var i = 0, values = []; i < length; i++) {
      var opt = element.options[i];
      if (opt.selected) values.push(this.optionValue(opt));
    }
    return values;
  },

  optionValue: function(opt) {
    // extend element because hasAttribute may not be native
    return Element.extend(opt).hasAttribute('value') ? opt.value : opt.text;
  }
}

/*--------------------------------------------------------------------------*/

Abstract.TimedObserver = function() {}
Abstract.TimedObserver.prototype = {
  initialize: function(element, frequency, callback) {
    this.frequency = frequency;
    this.element   = $(element);
    this.callback  = callback;

    this.lastValue = this.getValue();
    this.registerCallback();
  },

  registerCallback: function() {
    setInterval(this.onTimerEvent.bind(this), this.frequency * 1000);
  },

  onTimerEvent: function() {
    var value = this.getValue();
    var changed = ('string' == typeof this.lastValue && 'string' == typeof value
      ? this.lastValue != value : String(this.lastValue) != String(value));
    if (changed) {
      this.callback(this.element, value);
      this.lastValue = value;
    }
  }
}

Form.Element.Observer = Class.create();
Form.Element.Observer.prototype = Object.extend(new Abstract.TimedObserver(), {
  getValue: function() {
    return Form.Element.getValue(this.element);
  }
});

Form.Observer = Class.create();
Form.Observer.prototype = Object.extend(new Abstract.TimedObserver(), {
  getValue: function() {
    return Form.serialize(this.element);
  }
});

/*--------------------------------------------------------------------------*/

Abstract.EventObserver = function() {}
Abstract.EventObserver.prototype = {
  initialize: function(element, callback) {
    this.element  = $(element);
    this.callback = callback;

    this.lastValue = this.getValue();
    if (this.element.tagName.toLowerCase() == 'form')
      this.registerFormCallbacks();
    else
      this.registerCallback(this.element);
  },

  onElementEvent: function() {
    var value = this.getValue();
    if (this.lastValue != value) {
      this.callback(this.element, value);
      this.lastValue = value;
    }
  },

  registerFormCallbacks: function() {
    Form.getElements(this.element).each(this.registerCallback.bind(this));
  },

  registerCallback: function(element) {
    if (element.type) {
      switch (element.type.toLowerCase()) {
        case 'checkbox':
        case 'radio':
          Event.observe(element, 'click', this.onElementEvent.bind(this));
          break;
        default:
          Event.observe(element, 'change', this.onElementEvent.bind(this));
          break;
      }
    }
  }
}

Form.Element.EventObserver = Class.create();
Form.Element.EventObserver.prototype = Object.extend(new Abstract.EventObserver(), {
  getValue: function() {
    return Form.Element.getValue(this.element);
  }
});

Form.EventObserver = Class.create();
Form.EventObserver.prototype = Object.extend(new Abstract.EventObserver(), {
  getValue: function() {
    return Form.serialize(this.element);
  }
});
if (!window.Event) {
  var Event = new Object();
}

Object.extend(Event, {
  KEY_BACKSPACE: 8,
  KEY_TAB:       9,
  KEY_RETURN:   13,
  KEY_ESC:      27,
  KEY_LEFT:     37,
  KEY_UP:       38,
  KEY_RIGHT:    39,
  KEY_DOWN:     40,
  KEY_DELETE:   46,
  KEY_HOME:     36,
  KEY_END:      35,
  KEY_PAGEUP:   33,
  KEY_PAGEDOWN: 34,

  element: function(event) {
    return $(event.target || event.srcElement);
  },

  isLeftClick: function(event) {
    return (((event.which) && (event.which == 1)) ||
            ((event.button) && (event.button == 1)));
  },

  pointerX: function(event) {
    return event.pageX || (event.clientX +
      (document.documentElement.scrollLeft || document.body.scrollLeft));
  },

  pointerY: function(event) {
    return event.pageY || (event.clientY +
      (document.documentElement.scrollTop || document.body.scrollTop));
  },

  stop: function(event) {
    if (event.preventDefault) {
      event.preventDefault();
      event.stopPropagation();
    } else {
      event.returnValue = false;
      event.cancelBubble = true;
    }
  },

  // find the first node with the given tagName, starting from the
  // node the event was triggered on; traverses the DOM upwards
  findElement: function(event, tagName) {
    var element = Event.element(event);
    while (element.parentNode && (!element.tagName ||
        (element.tagName.toUpperCase() != tagName.toUpperCase())))
      element = element.parentNode;
    return element;
  },

  observers: false,

  _observeAndCache: function(element, name, observer, useCapture) {
    if (!this.observers) this.observers = [];
    if (element.addEventListener) {
      this.observers.push([element, name, observer, useCapture]);
      element.addEventListener(name, observer, useCapture);
    } else if (element.attachEvent) {
      this.observers.push([element, name, observer, useCapture]);
      element.attachEvent('on' + name, observer);
    }
  },

  unloadCache: function() {
    if (!Event.observers) return;
    for (var i = 0, length = Event.observers.length; i < length; i++) {
      Event.stopObserving.apply(this, Event.observers[i]);
      Event.observers[i][0] = null;
    }
    Event.observers = false;
  },

  observe: function(element, name, observer, useCapture) {
    element = $(element);
    useCapture = useCapture || false;

    if (name == 'keypress' &&
      (Prototype.Browser.WebKit || element.attachEvent))
      name = 'keydown';

    Event._observeAndCache(element, name, observer, useCapture);
  },

  stopObserving: function(element, name, observer, useCapture) {
    element = $(element);
    useCapture = useCapture || false;

    if (name == 'keypress' &&
        (Prototype.Browser.WebKit || element.attachEvent))
      name = 'keydown';

    if (element.removeEventListener) {
      element.removeEventListener(name, observer, useCapture);
    } else if (element.detachEvent) {
      try {
        element.detachEvent('on' + name, observer);
      } catch (e) {}
    }
  }
});

/* prevent memory leaks in IE */
if (Prototype.Browser.IE)
  Event.observe(window, 'unload', Event.unloadCache, false);
var Position = {
  // set to true if needed, warning: firefox performance problems
  // NOT neeeded for page scrolling, only if draggable contained in
  // scrollable elements
  includeScrollOffsets: false,

  // must be called before calling withinIncludingScrolloffset, every time the
  // page is scrolled
  prepare: function() {
    this.deltaX =  window.pageXOffset
                || document.documentElement.scrollLeft
                || document.body.scrollLeft
                || 0;
    this.deltaY =  window.pageYOffset
                || document.documentElement.scrollTop
                || document.body.scrollTop
                || 0;
  },

  realOffset: function(element) {
    var valueT = 0, valueL = 0;
    do {
      valueT += element.scrollTop  || 0;
      valueL += element.scrollLeft || 0;
      element = element.parentNode;
    } while (element);
    return [valueL, valueT];
  },

  cumulativeOffset: function(element) {
    var valueT = 0, valueL = 0;
    do {
      valueT += element.offsetTop  || 0;
      valueL += element.offsetLeft || 0;
      element = element.offsetParent;
    } while (element);
    return [valueL, valueT];
  },

  positionedOffset: function(element) {
    var valueT = 0, valueL = 0;
    do {
      valueT += element.offsetTop  || 0;
      valueL += element.offsetLeft || 0;
      element = element.offsetParent;
      if (element) {
        if(element.tagName=='BODY') break;
        var p = Element.getStyle(element, 'position');
        if (p == 'relative' || p == 'absolute') break;
      }
    } while (element);
    return [valueL, valueT];
  },

  offsetParent: function(element) {
    if (element.offsetParent) return element.offsetParent;
    if (element == document.body) return element;

    while ((element = element.parentNode) && element != document.body)
      if (Element.getStyle(element, 'position') != 'static')
        return element;

    return document.body;
  },

  // caches x/y coordinate pair to use with overlap
  within: function(element, x, y) {
    if (this.includeScrollOffsets)
      return this.withinIncludingScrolloffsets(element, x, y);
    this.xcomp = x;
    this.ycomp = y;
    this.offset = this.cumulativeOffset(element);

    return (y >= this.offset[1] &&
            y <  this.offset[1] + element.offsetHeight &&
            x >= this.offset[0] &&
            x <  this.offset[0] + element.offsetWidth);
  },

  withinIncludingScrolloffsets: function(element, x, y) {
    var offsetcache = this.realOffset(element);

    this.xcomp = x + offsetcache[0] - this.deltaX;
    this.ycomp = y + offsetcache[1] - this.deltaY;
    this.offset = this.cumulativeOffset(element);

    return (this.ycomp >= this.offset[1] &&
            this.ycomp <  this.offset[1] + element.offsetHeight &&
            this.xcomp >= this.offset[0] &&
            this.xcomp <  this.offset[0] + element.offsetWidth);
  },

  // within must be called directly before
  overlap: function(mode, element) {
    if (!mode) return 0;
    if (mode == 'vertical')
      return ((this.offset[1] + element.offsetHeight) - this.ycomp) /
        element.offsetHeight;
    if (mode == 'horizontal')
      return ((this.offset[0] + element.offsetWidth) - this.xcomp) /
        element.offsetWidth;
  },

  page: function(forElement) {
    var valueT = 0, valueL = 0;

    var element = forElement;
    do {
      valueT += element.offsetTop  || 0;
      valueL += element.offsetLeft || 0;

      // Safari fix
      if (element.offsetParent == document.body)
        if (Element.getStyle(element,'position')=='absolute') break;

    } while (element = element.offsetParent);

    element = forElement;
    do {
      if (!window.opera || element.tagName=='BODY') {
        valueT -= element.scrollTop  || 0;
        valueL -= element.scrollLeft || 0;
      }
    } while (element = element.parentNode);

    return [valueL, valueT];
  },

  clone: function(source, target) {
    var options = Object.extend({
      setLeft:    true,
      setTop:     true,
      setWidth:   true,
      setHeight:  true,
      offsetTop:  0,
      offsetLeft: 0
    }, arguments[2] || {})

    // find page position of source
    source = $(source);
    var p = Position.page(source);

    // find coordinate system to use
    target = $(target);
    var delta = [0, 0];
    var parent = null;
    // delta [0,0] will do fine with position: fixed elements,
    // position:absolute needs offsetParent deltas
    if (Element.getStyle(target,'position') == 'absolute') {
      parent = Position.offsetParent(target);
      delta = Position.page(parent);
    }

    // correct by body offsets (fixes Safari)
    if (parent == document.body) {
      delta[0] -= document.body.offsetLeft;
      delta[1] -= document.body.offsetTop;
    }

    // set position
    if(options.setLeft)   target.style.left  = (p[0] - delta[0] + options.offsetLeft) + 'px';
    if(options.setTop)    target.style.top   = (p[1] - delta[1] + options.offsetTop) + 'px';
    if(options.setWidth)  target.style.width = source.offsetWidth + 'px';
    if(options.setHeight) target.style.height = source.offsetHeight + 'px';
  },

  absolutize: function(element) {
    element = $(element);
    if (element.style.position == 'absolute') return;
    Position.prepare();

    var offsets = Position.positionedOffset(element);
    var top     = offsets[1];
    var left    = offsets[0];
    var width   = element.clientWidth;
    var height  = element.clientHeight;

    element._originalLeft   = left - parseFloat(element.style.left  || 0);
    element._originalTop    = top  - parseFloat(element.style.top || 0);
    element._originalWidth  = element.style.width;
    element._originalHeight = element.style.height;

    element.style.position = 'absolute';
    element.style.top    = top + 'px';
    element.style.left   = left + 'px';
    element.style.width  = width + 'px';
    element.style.height = height + 'px';
  },

  relativize: function(element) {
    element = $(element);
    if (element.style.position == 'relative') return;
    Position.prepare();

    element.style.position = 'relative';
    var top  = parseFloat(element.style.top  || 0) - (element._originalTop || 0);
    var left = parseFloat(element.style.left || 0) - (element._originalLeft || 0);

    element.style.top    = top + 'px';
    element.style.left   = left + 'px';
    element.style.height = element._originalHeight;
    element.style.width  = element._originalWidth;
  }
}

// Safari returns margins on body which is incorrect if the child is absolutely
// positioned.  For performance reasons, redefine Position.cumulativeOffset for
// KHTML/WebKit only.
if (Prototype.Browser.WebKit) {
  Position.cumulativeOffset = function(element) {
    var valueT = 0, valueL = 0;
    do {
      valueT += element.offsetTop  || 0;
      valueL += element.offsetLeft || 0;
      if (element.offsetParent == document.body)
        if (Element.getStyle(element, 'position') == 'absolute') break;

      element = element.offsetParent;
    } while (element);

    return [valueL, valueT];
  }
}

Element.addMethods();
// script.aculo.us scriptaculous.js v1.7.1_beta3, Fri May 25 17:19:41 +0200 2007

// Copyright (c) 2005-2007 Thomas Fuchs (http://script.aculo.us, http://mir.aculo.us)
// 
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
// 
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
// For details, see the script.aculo.us web site: http://script.aculo.us/

var Scriptaculous = {
  Version: '1.7.1_beta3',
  require: function(libraryName) {
    // inserting via DOM fails in Safari 2.0, so brute force approach
    document.write('<script type="text/javascript" src="'+libraryName+'"></script>');
  },
  REQUIRED_PROTOTYPE: '1.5.1',
  load: function() {
    function convertVersionString(versionString){
      var r = versionString.split('.');
      return parseInt(r[0])*100000 + parseInt(r[1])*1000 + parseInt(r[2]);
    }
 
    if((typeof Prototype=='undefined') || 
       (typeof Element == 'undefined') || 
       (typeof Element.Methods=='undefined') ||
       (convertVersionString(Prototype.Version) < 
        convertVersionString(Scriptaculous.REQUIRED_PROTOTYPE)))
       throw("script.aculo.us requires the Prototype JavaScript framework >= " +
        Scriptaculous.REQUIRED_PROTOTYPE);
    
    $A(document.getElementsByTagName("script")).findAll( function(s) {
      return (s.src && s.src.match(/scriptaculous\.js(\?.*)?$/))
    }).each( function(s) {
      var path = s.src.replace(/scriptaculous\.js(\?.*)?$/,'');
      var includes = s.src.match(/\?.*load=([a-z,]*)/);
      (includes ? includes[1] : 'builder,effects,dragdrop,controls,slider,sound').split(',').each(
       function(include) { Scriptaculous.require(path+include+'.js') });
    });
  }
}

Scriptaculous.load();
// script.aculo.us effects.js v1.7.1_beta3, Fri May 25 17:19:41 +0200 2007

// Copyright (c) 2005-2007 Thomas Fuchs (http://script.aculo.us, http://mir.aculo.us)
// Contributors:
//  Justin Palmer (http://encytemedia.com/)
//  Mark Pilgrim (http://diveintomark.org/)
//  Martin Bialasinki
// 
// script.aculo.us is freely distributable under the terms of an MIT-style license.
// For details, see the script.aculo.us web site: http://script.aculo.us/ 

// converts rgb() and #xxx to #xxxxxx format,  
// returns self (or first argument) if not convertable  
String.prototype.parseColor = function() {  
  var color = '#';
  if(this.slice(0,4) == 'rgb(') {  
    var cols = this.slice(4,this.length-1).split(',');  
    var i=0; do { color += parseInt(cols[i]).toColorPart() } while (++i<3);  
  } else {  
    if(this.slice(0,1) == '#') {  
      if(this.length==4) for(var i=1;i<4;i++) color += (this.charAt(i) + this.charAt(i)).toLowerCase();  
      if(this.length==7) color = this.toLowerCase();  
    }  
  }  
  return(color.length==7 ? color : (arguments[0] || this));  
}

/*--------------------------------------------------------------------------*/

Element.collectTextNodes = function(element) {  
  return $A($(element).childNodes).collect( function(node) {
    return (node.nodeType==3 ? node.nodeValue : 
      (node.hasChildNodes() ? Element.collectTextNodes(node) : ''));
  }).flatten().join('');
}

Element.collectTextNodesIgnoreClass = function(element, className) {  
  return $A($(element).childNodes).collect( function(node) {
    return (node.nodeType==3 ? node.nodeValue : 
      ((node.hasChildNodes() && !Element.hasClassName(node,className)) ? 
        Element.collectTextNodesIgnoreClass(node, className) : ''));
  }).flatten().join('');
}

Element.setContentZoom = function(element, percent) {
  element = $(element);  
  element.setStyle({fontSize: (percent/100) + 'em'});   
  if(Prototype.Browser.WebKit) window.scrollBy(0,0);
  return element;
}

Element.getInlineOpacity = function(element){
  return $(element).style.opacity || '';
}

Element.forceRerendering = function(element) {
  try {
    element = $(element);
    var n = document.createTextNode(' ');
    element.appendChild(n);
    element.removeChild(n);
  } catch(e) { }
};

/*--------------------------------------------------------------------------*/

Array.prototype.call = function() {
  var args = arguments;
  this.each(function(f){ f.apply(this, args) });
}

/*--------------------------------------------------------------------------*/

var Effect = {
  _elementDoesNotExistError: {
    name: 'ElementDoesNotExistError',
    message: 'The specified DOM element does not exist, but is required for this effect to operate'
  },
  tagifyText: function(element) {
    if(typeof Builder == 'undefined')
      throw("Effect.tagifyText requires including script.aculo.us' builder.js library");
      
    var tagifyStyle = 'position:relative';
    if(Prototype.Browser.IE) tagifyStyle += ';zoom:1';
    
    element = $(element);
    $A(element.childNodes).each( function(child) {
      if(child.nodeType==3) {
        child.nodeValue.toArray().each( function(character) {
          element.insertBefore(
            Builder.node('span',{style: tagifyStyle},
              character == ' ' ? String.fromCharCode(160) : character), 
              child);
        });
        Element.remove(child);
      }
    });
  },
  multiple: function(element, effect) {
    var elements;
    if(((typeof element == 'object') || 
        (typeof element == 'function')) && 
       (element.length))
      elements = element;
    else
      elements = $(element).childNodes;
      
    var options = Object.extend({
      speed: 0.1,
      delay: 0.0
    }, arguments[2] || {});
    var masterDelay = options.delay;

    $A(elements).each( function(element, index) {
      new effect(element, Object.extend(options, { delay: index * options.speed + masterDelay }));
    });
  },
  PAIRS: {
    'slide':  ['SlideDown','SlideUp'],
    'blind':  ['BlindDown','BlindUp'],
    'appear': ['Appear','Fade']
  },
  toggle: function(element, effect) {
    element = $(element);
    effect = (effect || 'appear').toLowerCase();
    var options = Object.extend({
      queue: { position:'end', scope:(element.id || 'global'), limit: 1 }
    }, arguments[2] || {});
    Effect[element.visible() ? 
      Effect.PAIRS[effect][1] : Effect.PAIRS[effect][0]](element, options);
  }
};

var Effect2 = Effect; // deprecated

/* ------------- transitions ------------- */

Effect.Transitions = {
  linear: Prototype.K,
  sinoidal: function(pos) {
    return (-Math.cos(pos*Math.PI)/2) + 0.5;
  },
  reverse: function(pos) {
    return 1-pos;
  },
  flicker: function(pos) {
    var pos = ((-Math.cos(pos*Math.PI)/4) + 0.75) + Math.random()/4;
    return (pos > 1 ? 1 : pos);
  },
  wobble: function(pos) {
    return (-Math.cos(pos*Math.PI*(9*pos))/2) + 0.5;
  },
  pulse: function(pos, pulses) { 
    pulses = pulses || 5; 
    return (
      Math.round((pos % (1/pulses)) * pulses) == 0 ? 
            ((pos * pulses * 2) - Math.floor(pos * pulses * 2)) : 
        1 - ((pos * pulses * 2) - Math.floor(pos * pulses * 2))
      );
  },
  none: function(pos) {
    return 0;
  },
  full: function(pos) {
    return 1;
  }
};

/* ------------- core effects ------------- */

Effect.ScopedQueue = Class.create();
Object.extend(Object.extend(Effect.ScopedQueue.prototype, Enumerable), {
  initialize: function() {
    this.effects  = [];
    this.interval = null;    
  },
  _each: function(iterator) {
    this.effects._each(iterator);
  },
  add: function(effect) {
    var timestamp = new Date().getTime();
    
    var position = (typeof effect.options.queue == 'string') ? 
      effect.options.queue : effect.options.queue.position;
    
    switch(position) {
      case 'front':
        // move unstarted effects after this effect  
        this.effects.findAll(function(e){ return e.state=='idle' }).each( function(e) {
            e.startOn  += effect.finishOn;
            e.finishOn += effect.finishOn;
          });
        break;
      case 'with-last':
        timestamp = this.effects.pluck('startOn').max() || timestamp;
        break;
      case 'end':
        // start effect after last queued effect has finished
        timestamp = this.effects.pluck('finishOn').max() || timestamp;
        break;
    }
    
    effect.startOn  += timestamp;
    effect.finishOn += timestamp;

    if(!effect.options.queue.limit || (this.effects.length < effect.options.queue.limit))
      this.effects.push(effect);
    
    if(!this.interval)
      this.interval = setInterval(this.loop.bind(this), 15);
  },
  remove: function(effect) {
    this.effects = this.effects.reject(function(e) { return e==effect });
    if(this.effects.length == 0) {
      clearInterval(this.interval);
      this.interval = null;
    }
  },
  loop: function() {
    var timePos = new Date().getTime();
    for(var i=0, len=this.effects.length;i<len;i++) 
      this.effects[i] && this.effects[i].loop(timePos);
  }
});

Effect.Queues = {
  instances: $H(),
  get: function(queueName) {
    if(typeof queueName != 'string') return queueName;
    
    if(!this.instances[queueName])
      this.instances[queueName] = new Effect.ScopedQueue();
      
    return this.instances[queueName];
  }
}
Effect.Queue = Effect.Queues.get('global');

Effect.DefaultOptions = {
  transition: Effect.Transitions.sinoidal,
  duration:   1.0,   // seconds
  fps:        100,   // 100= assume 66fps max.
  sync:       false, // true for combining
  from:       0.0,
  to:         1.0,
  delay:      0.0,
  queue:      'parallel'
}

Effect.Base = function() {};
Effect.Base.prototype = {
  position: null,
  start: function(options) {
    function codeForEvent(options,eventName){
      return (
        (options[eventName+'Internal'] ? 'this.options.'+eventName+'Internal(this);' : '') +
        (options[eventName] ? 'this.options.'+eventName+'(this);' : '')
      );
    }
    if(options.transition === false) options.transition = Effect.Transitions.linear;
    this.options      = Object.extend(Object.extend({},Effect.DefaultOptions), options || {});
    this.currentFrame = 0;
    this.state        = 'idle';
    this.startOn      = this.options.delay*1000;
    this.finishOn     = this.startOn+(this.options.duration*1000);
    this.fromToDelta  = this.options.to-this.options.from;
    this.totalTime    = this.finishOn-this.startOn;
    this.totalFrames  = this.options.fps*this.options.duration;
    
    eval('this.render = function(pos){ '+
      'if(this.state=="idle"){this.state="running";'+
      codeForEvent(options,'beforeSetup')+
      (this.setup ? 'this.setup();':'')+ 
      codeForEvent(options,'afterSetup')+
      '};if(this.state=="running"){'+
      'pos=this.options.transition(pos)*'+this.fromToDelta+'+'+this.options.from+';'+
      'this.position=pos;'+
      codeForEvent(options,'beforeUpdate')+
      (this.update ? 'this.update(pos);':'')+
      codeForEvent(options,'afterUpdate')+
      '}}');
    
    this.event('beforeStart');
    if(!this.options.sync)
      Effect.Queues.get(typeof this.options.queue == 'string' ? 
        'global' : this.options.queue.scope).add(this);
  },
  loop: function(timePos) {
    if(timePos >= this.startOn) {
      if(timePos >= this.finishOn) {
        this.render(1.0);
        this.cancel();
        this.event('beforeFinish');
        if(this.finish) this.finish(); 
        this.event('afterFinish');
        return;  
      }
      var pos   = (timePos - this.startOn) / this.totalTime,
          frame = Math.round(pos * this.totalFrames);
      if(frame > this.currentFrame) {
        this.render(pos);
        this.currentFrame = frame;
      }
    }
  },
  cancel: function() {
    if(!this.options.sync)
      Effect.Queues.get(typeof this.options.queue == 'string' ? 
        'global' : this.options.queue.scope).remove(this);
    this.state = 'finished';
  },
  event: function(eventName) {
    if(this.options[eventName + 'Internal']) this.options[eventName + 'Internal'](this);
    if(this.options[eventName]) this.options[eventName](this);
  },
  inspect: function() {
    var data = $H();
    for(property in this)
      if(typeof this[property] != 'function') data[property] = this[property];
    return '#<Effect:' + data.inspect() + ',options:' + $H(this.options).inspect() + '>';
  }
}

Effect.Parallel = Class.create();
Object.extend(Object.extend(Effect.Parallel.prototype, Effect.Base.prototype), {
  initialize: function(effects) {
    this.effects = effects || [];
    this.start(arguments[1]);
  },
  update: function(position) {
    this.effects.invoke('render', position);
  },
  finish: function(position) {
    this.effects.each( function(effect) {
      effect.render(1.0);
      effect.cancel();
      effect.event('beforeFinish');
      if(effect.finish) effect.finish(position);
      effect.event('afterFinish');
    });
  }
});

Effect.Event = Class.create();
Object.extend(Object.extend(Effect.Event.prototype, Effect.Base.prototype), {
  initialize: function() {
    var options = Object.extend({
      duration: 0
    }, arguments[0] || {});
    this.start(options);
  },
  update: Prototype.emptyFunction
});

Effect.Opacity = Class.create();
Object.extend(Object.extend(Effect.Opacity.prototype, Effect.Base.prototype), {
  initialize: function(element) {
    this.element = $(element);
    if(!this.element) throw(Effect._elementDoesNotExistError);
    // make this work on IE on elements without 'layout'
    if(Prototype.Browser.IE && (!this.element.currentStyle.hasLayout))
      this.element.setStyle({zoom: 1});
    var options = Object.extend({
      from: this.element.getOpacity() || 0.0,
      to:   1.0
    }, arguments[1] || {});
    this.start(options);
  },
  update: function(position) {
    this.element.setOpacity(position);
  }
});

Effect.Move = Class.create();
Object.extend(Object.extend(Effect.Move.prototype, Effect.Base.prototype), {
  initialize: function(element) {
    this.element = $(element);
    if(!this.element) throw(Effect._elementDoesNotExistError);
    var options = Object.extend({
      x:    0,
      y:    0,
      mode: 'relative'
    }, arguments[1] || {});
    this.start(options);
  },
  setup: function() {
    // Bug in Opera: Opera returns the "real" position of a static element or
    // relative element that does not have top/left explicitly set.
    // ==> Always set top and left for position relative elements in your stylesheets 
    // (to 0 if you do not need them) 
    this.element.makePositioned();
    this.originalLeft = parseFloat(this.element.getStyle('left') || '0');
    this.originalTop  = parseFloat(this.element.getStyle('top')  || '0');
    if(this.options.mode == 'absolute') {
      // absolute movement, so we need to calc deltaX and deltaY
      this.options.x = this.options.x - this.originalLeft;
      this.options.y = this.options.y - this.originalTop;
    }
  },
  update: function(position) {
    this.element.setStyle({
      left: Math.round(this.options.x  * position + this.originalLeft) + 'px',
      top:  Math.round(this.options.y  * position + this.originalTop)  + 'px'
    });
  }
});

// for backwards compatibility
Effect.MoveBy = function(element, toTop, toLeft) {
  return new Effect.Move(element, 
    Object.extend({ x: toLeft, y: toTop }, arguments[3] || {}));
};

Effect.Scale = Class.create();
Object.extend(Object.extend(Effect.Scale.prototype, Effect.Base.prototype), {
  initialize: function(element, percent) {
    this.element = $(element);
    if(!this.element) throw(Effect._elementDoesNotExistError);
    var options = Object.extend({
      scaleX: true,
      scaleY: true,
      scaleContent: true,
      scaleFromCenter: false,
      scaleMode: 'box',        // 'box' or 'contents' or {} with provided values
      scaleFrom: 100.0,
      scaleTo:   percent
    }, arguments[2] || {});
    this.start(options);
  },
  setup: function() {
    this.restoreAfterFinish = this.options.restoreAfterFinish || false;
    this.elementPositioning = this.element.getStyle('position');
    
    this.originalStyle = {};
    ['top','left','width','height','fontSize'].each( function(k) {
      this.originalStyle[k] = this.element.style[k];
    }.bind(this));
      
    this.originalTop  = this.element.offsetTop;
    this.originalLeft = this.element.offsetLeft;
    
    var fontSize = this.element.getStyle('font-size') || '100%';
    ['em','px','%','pt'].each( function(fontSizeType) {
      if(fontSize.indexOf(fontSizeType)>0) {
        this.fontSize     = parseFloat(fontSize);
        this.fontSizeType = fontSizeType;
      }
    }.bind(this));
    
    this.factor = (this.options.scaleTo - this.options.scaleFrom)/100;
    
    this.dims = null;
    if(this.options.scaleMode=='box')
      this.dims = [this.element.offsetHeight, this.element.offsetWidth];
    if(/^content/.test(this.options.scaleMode))
      this.dims = [this.element.scrollHeight, this.element.scrollWidth];
    if(!this.dims)
      this.dims = [this.options.scaleMode.originalHeight,
                   this.options.scaleMode.originalWidth];
  },
  update: function(position) {
    var currentScale = (this.options.scaleFrom/100.0) + (this.factor * position);
    if(this.options.scaleContent && this.fontSize)
      this.element.setStyle({fontSize: this.fontSize * currentScale + this.fontSizeType });
    this.setDimensions(this.dims[0] * currentScale, this.dims[1] * currentScale);
  },
  finish: function(position) {
    if(this.restoreAfterFinish) this.element.setStyle(this.originalStyle);
  },
  setDimensions: function(height, width) {
    var d = {};
    if(this.options.scaleX) d.width = Math.round(width) + 'px';
    if(this.options.scaleY) d.height = Math.round(height) + 'px';
    if(this.options.scaleFromCenter) {
      var topd  = (height - this.dims[0])/2;
      var leftd = (width  - this.dims[1])/2;
      if(this.elementPositioning == 'absolute') {
        if(this.options.scaleY) d.top = this.originalTop-topd + 'px';
        if(this.options.scaleX) d.left = this.originalLeft-leftd + 'px';
      } else {
        if(this.options.scaleY) d.top = -topd + 'px';
        if(this.options.scaleX) d.left = -leftd + 'px';
      }
    }
    this.element.setStyle(d);
  }
});

Effect.Highlight = Class.create();
Object.extend(Object.extend(Effect.Highlight.prototype, Effect.Base.prototype), {
  initialize: function(element) {
    this.element = $(element);
    if(!this.element) throw(Effect._elementDoesNotExistError);
    var options = Object.extend({ startcolor: '#ffff99' }, arguments[1] || {});
    this.start(options);
  },
  setup: function() {
    // Prevent executing on elements not in the layout flow
    if(this.element.getStyle('display')=='none') { this.cancel(); return; }
    // Disable background image during the effect
    this.oldStyle = {};
    if (!this.options.keepBackgroundImage) {
      this.oldStyle.backgroundImage = this.element.getStyle('background-image');
      this.element.setStyle({backgroundImage: 'none'});
    }
    if(!this.options.endcolor)
      this.options.endcolor = this.element.getStyle('background-color').parseColor('#ffffff');
    if(!this.options.restorecolor)
      this.options.restorecolor = this.element.getStyle('background-color');
    // init color calculations
    this._base  = $R(0,2).map(function(i){ return parseInt(this.options.startcolor.slice(i*2+1,i*2+3),16) }.bind(this));
    this._delta = $R(0,2).map(function(i){ return parseInt(this.options.endcolor.slice(i*2+1,i*2+3),16)-this._base[i] }.bind(this));
  },
  update: function(position) {
    this.element.setStyle({backgroundColor: $R(0,2).inject('#',function(m,v,i){
      return m+(Math.round(this._base[i]+(this._delta[i]*position)).toColorPart()); }.bind(this)) });
  },
  finish: function() {
    this.element.setStyle(Object.extend(this.oldStyle, {
      backgroundColor: this.options.restorecolor
    }));
  }
});

Effect.ScrollTo = Class.create();
Object.extend(Object.extend(Effect.ScrollTo.prototype, Effect.Base.prototype), {
  initialize: function(element) {
    this.element = $(element);
    this.start(arguments[1] || {});
  },
  setup: function() {
    Position.prepare();
    var offsets = Position.cumulativeOffset(this.element);
    if(this.options.offset) offsets[1] += this.options.offset;
    var max = window.innerHeight ? 
      window.height - window.innerHeight :
      document.body.scrollHeight - 
        (document.documentElement.clientHeight ? 
          document.documentElement.clientHeight : document.body.clientHeight);
    this.scrollStart = Position.deltaY;
    this.delta = (offsets[1] > max ? max : offsets[1]) - this.scrollStart;
  },
  update: function(position) {
    Position.prepare();
    window.scrollTo(Position.deltaX, 
      this.scrollStart + (position*this.delta));
  }
});

/* ------------- combination effects ------------- */

Effect.Fade = function(element) {
  element = $(element);
  var oldOpacity = element.getInlineOpacity();
  var options = Object.extend({
  from: element.getOpacity() || 1.0,
  to:   0.0,
  afterFinishInternal: function(effect) { 
    if(effect.options.to!=0) return;
    effect.element.hide().setStyle({opacity: oldOpacity}); 
  }}, arguments[1] || {});
  return new Effect.Opacity(element,options);
}

Effect.Appear = function(element) {
  element = $(element);
  var options = Object.extend({
  from: (element.getStyle('display') == 'none' ? 0.0 : element.getOpacity() || 0.0),
  to:   1.0,
  // force Safari to render floated elements properly
  afterFinishInternal: function(effect) {
    effect.element.forceRerendering();
  },
  beforeSetup: function(effect) {
    effect.element.setOpacity(effect.options.from).show(); 
  }}, arguments[1] || {});
  return new Effect.Opacity(element,options);
}

Effect.Puff = function(element) {
  element = $(element);
  var oldStyle = { 
    op