var XMLHttp =
{
    Xpool: [],
    getX: function()
    {
        this.Xpool[this.Xpool.length] = this.createX();
        return this.Xpool[this.Xpool.length - 1];
    },
    createX: function()
    {
        if(window.ActiveXObject)
        {
            try
            {
                //IE 5.0+
                var X = new ActiveXObject("Microsoft.XMLHTTP");
            }
            catch (e)
            {
                try
                {
                    //IE 5.0 -
                    var X = new ActiveXObject("Msxml2.XMLHTTP");
                }
                catch (e){alert(e);}
            }
        }
        else if(window.XMLHttpRequest)
        {
            //mozilla 1.0+  safari 1.2+
            try
            {
                var X = new XMLHttpRequest();
                if(X.overrideMimeType)
                {
　　                X.overrideMimeType("text/xml");
　                }
            }
            catch(e){alert(e);}    
        }
        return X;
    },
    getR: function(url,callback,type)
    {
        var Xobj = this.getX();
        try
        {
            if (url.indexOf("?") > 0)
            {
                url += "&randnum=" + Math.random();
            }
            else
            {
                url += "?randnum=" + Math.random();
            }
            Xobj.onreadystatechange = function ()
            {                   
                if (Xobj.readyState == 4)
                {
                    if(Xobj.status == 200)
                    {
                        if(type=='xml')
                        {
                            callback(Xobj.responseXML);
                        }
                        else
                        {
                            callback(Xobj.responseText);
                        }
                    }
                    else
                    {
                        alert("There was a problem with the request:"+Xobj.statusText);
                    }
                }
                else
                {
                    callback();
                }
            };
            Xobj.open("GET", url, true);
            Xobj.send(null);
        }
        catch(e)
        {
            alert(e);
        }
    },
    sendR: function(method, url, data, callback)
    {
        var    Xobj = this.getX();
        try
        {
            if (url.indexOf("?") > 0)
            {
                url += "&randnum=" + Math.random();
            }
            else
            {
                url += "?randnum=" + Math.random();
            }
            Xobj.open(method, url, true);
            Xobj.setRequestHeader("Content-Length",data.length);    
            Xobj.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded; charset=GBK');
            Xobj.send(data);
            Xobj.onreadystatechange = function ()
            {                   
                if (Xobj.readyState == 4 && (Xobj.status == 200 || Xobj.status == 304))
                {
                    callback(Xobj.responseXML);
                }
            };
        }
        catch(e)
        {
            alert(e);
        }
    }
};