var Ajax = {
  getTransport: function() {
    return Try.these(
      function() {return new ActiveXObject('MSXML2.XMLHTTP')},
      function() {return new ActiveXObject('Microsoft.XMLHTTP')},
      function() {return new ActiveXObject('MSXML2.XMLHTTP.5.0')},
      function() {return new ActiveXObject('MSXML2.XMLHTTP.4.0')},
      function() {return new ActiveXObject('MSXML2.XMLHTTP.3.0')},
      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' && parameters.length > 0)
        this.url += (this.url.match(/\?/) ? '&' : '?') + parameters; 

      this.transport.open(this.options.method, url,
        this.options.asynchronous);
	
	  //window.open(url);	
    
	  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;
	  //alert(url + '\n' + body);
      this.transport.send(this.options.method == 'post' ? body : null);

    } catch (e) {
    }
  },

  setRequestHeaders: function(url) {
    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);
  },

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