function CallBackObject()
{
  this.XmlHttp = this.GetHttpObject();
}
 
CallBackObject.prototype.GetHttpObject = function()
{ 
  var xmlhttp;
  /*@cc_on
  @if (@_jscript_version >= 5)
    try {
      xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
    } catch (e) {
      try {
        xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
      } catch (E) {
        xmlhttp = false;
      }
    }
  @else
  xmlhttp = false;
  @end @*/
  if (!xmlhttp && typeof XMLHttpRequest != 'undefined') {
    try {
           xmlhttp = new XMLHttpRequest();
	   if (http_request.overrideMimeType)
	   {
                //http_request.overrideMimeType('text/xml');
           }
        } 
    catch (e) {
    xmlhttp = false;
    }
  }
  return xmlhttp;
}
 
CallBackObject.prototype.DoCallBack = function(URL)
{ 
  if( this.XmlHttp )
  {
    if( this.XmlHttp.readyState == 4 || this.XmlHttp.readyState == 0 )
    {
      var oThis = this;
      this.XmlHttp.open('GET', URL, true);
      //this.XmlHttp.open('POST', URL);
      this.XmlHttp.onreadystatechange = function(){ oThis.ReadyStateChange(); };
      this.XmlHttp.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
      this.XmlHttp.send(null);
    }
  }
}
 
CallBackObject.prototype.AbortCallBack = function()
{
  if( this.XmlHttp )
    this.XmlHttp.abort();
}
 
CallBackObject.prototype.OnLoading = function()
{
  // Loading
}
 
CallBackObject.prototype.OnLoaded = function()
{
  // Loaded
}
 
CallBackObject.prototype.OnInteractive = function()
{
  // Interactive
}
 
CallBackObject.prototype.OnComplete = function(responseText, responseXml)
{
  // Complete
}
 
CallBackObject.prototype.OnAbort = function()
{
  // Abort
}
 
CallBackObject.prototype.OnError = function(status, statusText , responseText)
{
   alert("Ajax Error\nError Code:" + status + "\nError Description:" + statusText);
}
 
//readyState=如下
//0 (未初始化) 对象已建立，但是尚未初始化（尚未调用open方法） 
//1 (初始化) 对象已建立，尚未调用send方法 
//2 (发送数据) send方法已调用，但是当前的状态及http头未知 
//3 (数据传送中) 已接收部分数据，因为响应及http头不全，这时通过responseBody和responseText获取部分数据会出现错误， 
//4 (完成) 数据接收完毕,此时可以通过通过responseBody和responseText获取完整的回应数据 
CallBackObject.prototype.ReadyStateChange = function()
{
  if( this.XmlHttp.readyState == 1 )
  {
    this.OnLoading();
  }
  else if( this.XmlHttp.readyState == 2 )
  {
   this.OnLoaded();
  }
  else if( this.XmlHttp.readyState == 3 )
  {
   this.OnInteractive();
  }
  else if( this.XmlHttp.readyState == 4 )
  {
   if( this.XmlHttp.status == 0 )
      this.OnAbort();
    else if( this.XmlHttp.status == 200 && this.XmlHttp.statusText == "OK" )
      this.OnComplete(this.XmlHttp.responseText, this.XmlHttp.responseXML);
    else
      this.OnError(this.XmlHttp.status, this.XmlHttp.statusText, this.XmlHttp.responseText);   
  }
}