Metacat

/*  Prototype JavaScript framework, version 1.3.1

 *  (c) 2005 Sam Stephenson <sam@conio.net>

 *

 *  THIS FILE IS AUTOMATICALLY GENERATED. When sending patches, please diff

 *  against the source tree, available from the Prototype darcs repository. 

 *

 *  Prototype is freely distributable under the terms of an MIT-style license.

 *

 *  For details, see the Prototype web site: http://prototype.conio.net/

 *

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

var Prototype = {

  Version: '1.3.1',

  emptyFunction: function() {}

}

var Class = {

  create: function() {

    return function() { 

      this.initialize.apply(this, arguments);

    }

  }

}

var Abstract = new Object();

Object.extend = function(destination, source) {

  for (property in source) {

    destination[property] = source[property];

  }

  return destination;

}

Object.prototype.extend = function(object) {

  return Object.extend.apply(this, [this, object]);

}

Function.prototype.bind = function(object) {

  var __method = this;

  return function() {

    __method.apply(object, arguments);

  }

}

Function.prototype.bindAsEventListener = function(object) {

  var __method = this;

  return function(event) {

    __method.call(object, event || window.event);

  }

}

Number.prototype.toColorPart = function() {

  var digits = this.toString(16);

  if (this < 16) return '0' + digits;

  return digits;

}

var Try = {

  these: function() {

    var returnValue;

    for (var i = 0; i < arguments.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() {

    setInterval(this.onTimerEvent.bind(this), this.frequency * 1000);

  },

  onTimerEvent: function() {

    if (!this.currentlyExecuting) {

      try { 

        this.currentlyExecuting = true;

        this.callback(); 

      } finally { 

        this.currentlyExecuting = false;

      }

    }

  }

}

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

function $() {

  var elements = new Array();

  for (var i = 0; i < arguments.length; i++) {

    var element = arguments[i];

    if (typeof element == 'string')

      element = document.getElementById(element);

    if (arguments.length == 1) 

      return element;

    elements.push(element);

  }

  return elements;

}

if (!Array.prototype.push) {

  Array.prototype.push = function() {

		var startLength = this.length;

		for (var i = 0; i < arguments.length; i++)

      this[startLength + i] = arguments[i];

	  return this.length;

  }

}

if (!Function.prototype.apply) {

  // Based on code from http://www.youngpup.net/

  Function.prototype.apply = function(object, parameters) {

    var parameterStrings = new Array();

    if (!object)     object = window;

    if (!parameters) parameters = new Array();

    for (var i = 0; i < parameters.length; i++)

      parameterStrings[i] = 'parameters[' + i + ']';

    object.__apply__ = this;

    var result = eval('object.__apply__(' + 

      parameterStrings.join(', ') + ')');

    object.__apply__ = null;

    return result;

  }

}

String.prototype.extend({

  stripTags: function() {

    return this.replace(/<\/?[^>]+>/gi, '');

  },

  escapeHTML: function() {

    var div = document.createElement('div');

    var text = document.createTextNode(this);

    div.appendChild(text);

    return div.innerHTML;

  },

  unescapeHTML: function() {

    var div = document.createElement('div');

    div.innerHTML = this.stripTags();

    return div.childNodes[0].nodeValue;

  }

});

var Ajax = {

  getTransport: function() {

    return Try.these(

      function() {return new ActiveXObject('Msxml2.XMLHTTP')},

      function() {return new ActiveXObject('Microsoft.XMLHTTP')},

      function() {return new XMLHttpRequest()}

    ) || false;

  }

}

Ajax.Base = function() {};

Ajax.Base.prototype = {

  setOptions: function(options) {

    this.options = {

      method:       'post',

      asynchronous: true,

      parameters:   ''

    }.extend(options || {});

  },

  responseIsSuccess: function() {

    return this.transport.status == undefined

        || this.transport.status == 0 

        || (this.transport.status >= 200 && this.transport.status < 300);

  },

  responseIsFailure: function() {

    return !this.responseIsSuccess();

  }

}

Ajax.Request = Class.create();

Ajax.Request.Events = 

  ['Uninitialized', 'Loading', 'Loaded', 'Interactive', 'Complete'];

Ajax.Request.prototype = (new Ajax.Base()).extend({

  initialize: function(url, options) {

    this.transport = Ajax.getTransport();

    this.setOptions(options);

    this.request(url);

  },

  request: function(url) {

    var parameters = this.options.parameters || '';

    if (parameters.length > 0) parameters += '&_=';

    try {

      if (this.options.method == 'get')

        url += '?' + parameters;

      this.transport.open(this.options.method, url,

        this.options.asynchronous);

      if (this.options.asynchronous) {

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

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

      }

      this.setRequestHeaders();

      var body = this.options.postBody ? this.options.postBody : parameters;

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

    } catch (e) {

    }

  },

  setRequestHeaders: function() {

    var requestHeaders = 

      ['X-Requested-With', 'XMLHttpRequest',

       'X-Prototype-Version', Prototype.Version];

    if (this.options.method == 'post') {

      requestHeaders.push('Content-type', 

        'application/x-www-form-urlencoded');

      /* Force "Connection: close" for Mozilla browsers to work around

       * a bug where XMLHttpReqeuest sends an incorrect Content-length

       * header. See Mozilla Bugzilla #246651. 

       */

      if (this.transport.overrideMimeType)

        requestHeaders.push('Connection', 'close');

    }

    if (this.options.requestHeaders)

      requestHeaders.push.apply(requestHeaders, this.options.requestHeaders);

    for (var i = 0; i < requestHeaders.length; i += 2)

      this.transport.setRequestHeader(requestHeaders[i], requestHeaders[i+1]);

  },

  onStateChange: function() {

    var readyState = this.transport.readyState;

    if (readyState != 1)

      this.respondToReadyState(this.transport.readyState);

  },

  respondToReadyState: function(readyState) {

    var event = Ajax.Request.Events[readyState];

    if (event == 'Complete')

      (this.options['on' + this.transport.status]

       || this.options['on' + (this.responseIsSuccess() ? 'Success' : 'Failure')]

       || Prototype.emptyFunction)(this.transport);

    (this.options['on' + event] || Prototype.emptyFunction)(this.transport);

    /* Avoid memory leak in MSIE: clean up the oncomplete event handler */

    if (event == 'Complete')

      this.transport.onreadystatechange = Prototype.emptyFunction;

  }

});

Ajax.Updater = Class.create();

Ajax.Updater.ScriptFragment = '(?:<script.*?>)((\n|.)*?)(?:<\/script>)';

Ajax.Updater.prototype.extend(Ajax.Request.prototype).extend({

  initialize: function(container, url, options) {

    this.containers = {

      success: container.success ? $(container.success) : $(container),

      failure: 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() {

      this.updateContent();

      onComplete(this.transport);

    }).bind(this);

    this.request(url);

  },

  updateContent: function() {

    var receiver = this.responseIsSuccess() ?

      this.containers.success : this.containers.failure;

    var match    = new RegExp(Ajax.Updater.ScriptFragment, 'img');

    var response = this.transport.responseText.replace(match, '');

    var scripts  = this.transport.responseText.match(match);

    if (receiver) {

      if (this.options.insertion) {

        new this.options.insertion(receiver, response);

      } else {

        receiver.innerHTML = response;

      }

    }

    if (this.responseIsSuccess()) {

      if (this.onComplete)

        setTimeout((function() {this.onComplete(

          this.transport)}).bind(this), 10);

    }

    if (this.options.evalScripts && scripts) {

      match = new RegExp(Ajax.Updater.ScriptFragment, 'im');

      setTimeout((function() {

        for (var i = 0; i < scripts.length; i++)

          eval(scripts[i].match(match)[1]);

      }).bind(this), 10);

    }

  }

});

Ajax.PeriodicalUpdater = Class.create();

Ajax.PeriodicalUpdater.prototype = (new Ajax.Base()).extend({

  initialize: function(container, url, options) {

    this.setOptions(options);

    this.onComplete = this.options.onComplete;

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

    this.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.onComplete = undefined;

    clearTimeout(this.timer);

    (this.onComplete || Ajax.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);

  }

});

document.getElementsByClassName = function(className) {

  var children = document.getElementsByTagName('*') || document.all;

  var elements = new Array();

  for (var i = 0; i < children.length; i++) {

    var child = children[i];

    var classNames = child.className.split(' ');

    for (var j = 0; j < classNames.length; j++) {

      if (classNames[j] == className) {

        elements.push(child);

        break;

      }

    }

  }

  return elements;

}

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

if (!window.Element) {

  var Element = new Object();

}

Object.extend(Element, {

  toggle: function() {

    for (var i = 0; i < arguments.length; i++) {

      var element = $(arguments[i]);

      element.style.display = 

        (element.style.display == 'none' ? '' : 'none');

    }

  },

  hide: function() {

    for (var i = 0; i < arguments.length; i++) {

      var element = $(arguments[i]);

      element.style.display = 'none';

    }

  },

  show: function() {

    for (var i = 0; i < arguments.length; i++) {

      var element = $(arguments[i]);

      element.style.display = '';

    }

  },

  remove: function(element) {

    element = $(element);

    element.parentNode.removeChild(element);

  },

  getHeight: function(element) {

    element = $(element);

    return element.offsetHeight; 

  },

  hasClassName: function(element, className) {

    element = $(element);

    if (!element)

      return;

    var a = element.className.split(' ');

    for (var i = 0; i < a.length; i++) {

      if (a[i] == className)

        return true;

    }

    return false;

  },

  addClassName: function(element, className) {

    element = $(element);

    Element.removeClassName(element, className);

    element.className += ' ' + className;

  },

  removeClassName: function(element, className) {

    element = $(element);

    if (!element)

      return;

    var newClassName = '';

    var a = element.className.split(' ');

    for (var i = 0; i < a.length; i++) {

      if (a[i] != className) {

        if (i > 0)

          newClassName += ' ';

        newClassName += a[i];

      }

    }

    element.className = newClassName;

  },

  // removes whitespace-only text node children

  cleanWhitespace: function(element) {

    var element = $(element);

    for (var i = 0; i < element.childNodes.length; i++) {

      var node = element.childNodes[i];

      if (node.nodeType == 3 && !/\S/.test(node.nodeValue)) 

        Element.remove(node);

    }

  }

});

var Toggle = new Object();

Toggle.display = Element.toggle;

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

Abstract.Insertion = function(adjacency) {

  this.adjacency = adjacency;

}

Abstract.Insertion.prototype = {

  initialize: function(element, content) {

    this.element = $(element);

    this.content = content;

    if (this.adjacency && this.element.insertAdjacentHTML) {

      this.element.insertAdjacentHTML(this.adjacency, this.content);

    } else {

      this.range = this.element.ownerDocument.createRange();

      if (this.initializeRange) this.initializeRange();

      this.fragment = this.range.createContextualFragment(this.content);

      this.insertContent();

    }

  }

}

var Insertion = new Object();

Insertion.Before = Class.create();

Insertion.Before.prototype = (new Abstract.Insertion('beforeBegin')).extend({

  initializeRange: function() {

    this.range.setStartBefore(this.element);

  },

  insertContent: function() {

    this.element.parentNode.insertBefore(this.fragment, this.element);

  }

});

Insertion.Top = Class.create();

Insertion.Top.prototype = (new Abstract.Insertion('afterBegin')).extend({

  initializeRange: function() {

    this.range.selectNodeContents(this.element);

    this.range.collapse(true);

  },

  insertContent: function() {  

    this.element.insertBefore(this.fragment, this.element.firstChild);

  }

});

Insertion.Bottom = Class.create();

Insertion.Bottom.prototype = (new Abstract.Insertion('beforeEnd')).extend({

  initializeRange: function() {

    this.range.selectNodeContents(this.element);

    this.range.collapse(this.element);

  },

  insertContent: function() {

    this.element.appendChild(this.fragment);

  }

});

Insertion.After = Class.create();

Insertion.After.prototype = (new Abstract.Insertion('afterEnd')).extend({

  initializeRange: function() {

    this.range.setStartAfter(this.element);

  },

  insertContent: function() {

    this.element.parentNode.insertBefore(this.fragment, 

      this.element.nextSibling);

  }

});

var Field = {

  clear: function() {

    for (var i = 0; i < arguments.length; i++)

      $(arguments[i]).value = '';

  },

  focus: function(element) {

    $(element).focus();

  },

  present: function() {

    for (var i = 0; i < arguments.length; i++)

      if ($(arguments[i]).value == '') return false;

    return true;

  },

  select: function(element) {

    $(element).select();

  },

  activate: function(element) {

    $(element).focus();

    $(element).select();

  }

}

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

var Form = {

  serialize: function(form) {

    var elements = Form.getElements($(form));

    var queryComponents = new Array();

    for (var i = 0; i < elements.length; i++) {

      var queryComponent = Form.Element.serialize(elements[i]);

      if (queryComponent)

        queryComponents.push(queryComponent);

    }

    return queryComponents.join('&');

  },

  getElements: function(form) {

    var form = $(form);

    var elements = new Array();

    for (tagName in Form.Element.Serializers) {

      var tagElements = form.getElementsByTagName(tagName);

      for (var j = 0; j < tagElements.length; j++)

        elements.push(tagElements[j]);

    }

    return elements;

  },

  getInputs: function(form, typeName, name) {

    var form = $(form);

    var inputs = form.getElementsByTagName('input');

    if (!typeName && !name)

      return inputs;

    var matchingInputs = new Array();

    for (var i = 0; i < inputs.length; i++) {

      var input = inputs[i];

      if ((typeName && input.type != typeName) ||

          (name && input.name != name)) 

        continue;

      matchingInputs.push(input);

    }

    return matchingInputs;

  },

  disable: function(form) {

    var elements = Form.getElements(form);

    for (var i = 0; i < elements.length; i++) {

      var element = elements[i];

      element.blur();

      element.disabled = 'true';

    }

  },

  enable: function(form) {

    var elements = Form.getElements(form);

    for (var i = 0; i < elements.length; i++) {

      var element = elements[i];

      element.disabled = '';

    }

  },

  focusFirstElement: function(form) {

    var form = $(form);

    var elements = Form.getElements(form);

    for (var i = 0; i < elements.length; i++) {

      var element = elements[i];

      if (element.type != 'hidden' && !element.disabled) {

        Field.activate(element);

        break;

      }

    }

  },

  reset: function(form) {

    $(form).reset();

  }

}

Form.Element = {

  serialize: function(element) {

    var element = $(element);

    var method = element.tagName.toLowerCase();

    var parameter = Form.Element.Serializers[method](element);

    if (parameter)

      return encodeURIComponent(parameter[0]) + '=' + 

        encodeURIComponent(parameter[1]);                   

  },

  getValue: function(element) {

    var element = $(element);

    var method = element.tagName.toLowerCase();

    var parameter = Form.Element.Serializers[method](element);

    if (parameter) 

      return parameter[1];

  }

}

Form.Element.Serializers = {

  input: function(element) {

    switch (element.type.toLowerCase()) {

      case 'submit':

      case 'hidden':

      case 'password':

      case 'text':

        return Form.Element.Serializers.textarea(element);

      case 'checkbox':  

      case 'radio':

        return Form.Element.Serializers.inputSelector(element);

    }

    return false;

  },

  inputSelector: function(element) {

    if (element.checked)

      return [element.name, element.value];

  },

  textarea: function(element) {

    return [element.name, element.value];

  },

  select: function(element) {

    var value = '';

    if (element.type == 'select-one') {

      var index = element.selectedIndex;

      if (index >= 0)

        value = element.options[index].value || element.options[index].text;

    } else {

      value = new Array();

      for (var i = 0; i < element.length; i++) {

        var opt = element.options[i];

        if (opt.selected)

          value.push(opt.value || opt.text);

      }

    }

    return [element.name, value];

  }

}

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

var $F = Form.Element.getValue;

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

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();

    if (this.lastValue != value) {

      this.callback(this.element, value);

      this.lastValue = value;

    }

  }

}

Form.Element.Observer = Class.create();

Form.Element.Observer.prototype = (new Abstract.TimedObserver()).extend({

  getValue: function() {

    return Form.Element.getValue(this.element);

  }

});

Form.Observer = Class.create();

Form.Observer.prototype = (new Abstract.TimedObserver()).extend({

  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() {

    var elements = Form.getElements(this.element);

    for (var i = 0; i < elements.length; i++)

      this.registerCallback(elements[i]);

  },

  registerCallback: function(element) {

    if (element.type) {

      switch (element.type.toLowerCase()) {

        case 'checkbox':  

        case 'radio':

          element.target = this;

          element.prev_onclick = element.onclick || Prototype.emptyFunction;

          element.onclick = function() {

            this.prev_onclick(); 

            this.target.onElementEvent();

          }

          break;

        case 'password':

        case 'text':

        case 'textarea':

        case 'select-one':

        case 'select-multiple':

          element.target = this;

          element.prev_onchange = element.onchange || Prototype.emptyFunction;

          element.onchange = function() {

            this.prev_onchange(); 

            this.target.onElementEvent();

          }

          break;

      }

    }    

  }

}

Form.Element.EventObserver = Class.create();

Form.Element.EventObserver.prototype = (new Abstract.EventObserver()).extend({

  getValue: function() {

    return Form.Element.getValue(this.element);

  }

});

Form.EventObserver = Class.create();

Form.EventObserver.prototype = (new Abstract.EventObserver()).extend({

  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,

  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;

    }

  },

  // 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; i < Event.observers.length; i++) {

      Event.stopObserving.apply(this, Event.observers[i]);

      Event.observers[i][0] = null;

    }

    Event.observers = false;

  },

  observe: function(element, name, observer, useCapture) {

    var element = $(element);

    useCapture = useCapture || false;

    if (name == 'keypress' &&

        ((navigator.appVersion.indexOf('AppleWebKit') > 0) 

        || element.attachEvent))

      name = 'keydown';

    this._observeAndCache(element, name, observer, useCapture);

  },

  stopObserving: function(element, name, observer, useCapture) {

    var element = $(element);

    useCapture = useCapture || false;

    if (name == 'keypress' &&

        ((navigator.appVersion.indexOf('AppleWebKit') > 0) 

        || element.detachEvent))

      name = 'keydown';

    if (element.removeEventListener) {

      element.removeEventListener(name, observer, useCapture);

    } else if (element.detachEvent) {

      element.detachEvent('on' + name, observer);

    }

  }

});

/* prevent memory leaks in 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];

  },

  // 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;

  },

  clone: function(source, target) {

    source = $(source);

    target = $(target);

    target.style.position = 'absolute';

    var offsets = this.cumulativeOffset(source);

    target.style.top    = offsets[1] + 'px';

    target.style.left   = offsets[0] + 'px';

    target.style.width  = source.offsetWidth + 'px';

    target.style.height = source.offsetHeight + 'px';

  }

}