//Defined Ajax HttpRequest.
Ajax = function()
{
    var OnReceive = null;
    var xmlHttp = null;
    if (window.ActiveXObject)
    {
        xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
    }
    else if (window.XMLHttpRequest)
    {
        xmlHttp = new XMLHttpRequest();
    }
    
    if(xmlHttp.overrideMimeType)
	{
		xmlHttp.overrideMimeType("text/xml");
	}

    //do Request.
    this.doRequest = function(url,OnCallback)
    {
        //处理Firefox 安全问题
        if (window.netscape)  
        { 
            try  
            { 
              netscape.security.PrivilegeManager.enablePrivilege("UniversalBrowserRead"); 
            }  
            catch (e)  
            { 
               //alert("Permission UniversalBrowserRead denied."); 
            }
        }
        
        OnReceive = OnCallback;
        
        //true:异步;false:同步;
        xmlHttp.open("GET",url,true);
        xmlHttp.setRequestHeader("content-type","application/x-www-form-urlencoded");
        xmlHttp.onreadystatechange = this.doCallback;
        xmlHttp.send(null);
    }

    //do Callback.
    this.doCallback = function()
    {
      if (xmlHttp.readyState == 4)
      {
        var resText = "";
        
        if (xmlHttp.status == 200)
        {
            resText = xmlHttp.responseText;
            //return eval("(" + ResText + ")");
        }
        
        if (OnReceive)
        {
            //回调到指定方法
            OnReceive(resText);
        }
        else
        {
            return resText;
        }
      }
    }
}