var xmlhttp2;
var respone="";
function getListDataSource(_url){
  var url = _url;
  if(xmlhttp2&&xmlhttp2.readyState!=0&&xmlhttp2.readyState!=4){
       xmlhttp2.abort()
    }
    if(xmlhttp2)xmlhttp2.onreadystatechange=function(){};
    xmlhttp2 = getXMLHttpRequest();
    
    if(typeof(xmlhttp2) == "undefined"){
        alert("您的浏览器禁止了ActiveXObject的功能，请开放该项权限后再进行操作！");
        return ;
    }
    xmlhttp2.open("GET",_url, true);    
    xmlhttp2.onreadystatechange=function(){
         if(xmlhttp2.readyState == 4 ){
            if (xmlhttp2.status==200){
              if(xmlhttp2.responseText!=null&&xmlhttp2.responseText!="")
              {
              //alert(_url);
             // alert(xmlhttp2.responseText);
              respone=xmlhttp2.responseText;
              }
             }
         }
    };
    xmlhttp2.send(null); 
    return respone; 
}
function getXMLHttpRequest(){
    var MSXML = [ 'Microsoft.XMLHTTP', 'Msxml2.XMLHTTP','MSXML2.XMLHTTP.6.0', 'MSXML2.XMLHTTP.3.0', 'MSXML2.XMLHTTP.5.0', 'MSXML2.XMLHTTP.4.0']; 
    var a ; 
    for(var n = 0; n < MSXML.length; n++)
    { 
        try
        { 
	        a = new ActiveXObject(MSXML[n]); 
	        break; 
        }
        catch(e){
        }
        
     } 
     if(typeof(a)=="undefined"){
     try{
        a = new XMLHttpRequest;
     } catch(e){}
     }
    
     return a;
  } 

/*
* @param string		url 
* @param string		callback	回调函数 
* @param string		data		post数据 
*/ 
function iXmlHttpReq(url, callback, data) 
{ 
    // init 
    url += url.indexOf("?") >= 0 ? "&" : "?"; 
    url += "random_download_url=" + Math.random(); 
    if (typeof data == 'undefined') 
    { 
        var data = null; 
    } 
    method = data ? 'POST' : 'GET'; 
    // create XMLHttpRequest object 
    if (window.XMLHttpRequest) { 
        var objXMLHttpRequest = new XMLHttpRequest(); 
    } else { 
        var MSXML = ['MSXML2.XMLHTTP.6.0', 'MSXML2.XMLHTTP.3.0', 'MSXML2.XMLHTTP.5.0', 'MSXML2.XMLHTTP.4.0', 'MSXML2.XMLHTTP', 'Microsoft.XMLHTTP']; 
        for(var n = 0; n < MSXML.length; n ++) { 
            try { 
                var objXMLHttpRequest = new ActiveXObject(MSXML[n]); 
                break; 
            } catch(e) {
                //alert(e.message);
            } 
        } 
    } 
    // send request 
    with(objXMLHttpRequest) { 
        //setTimeouts(30*1000,30*1000,30*1000,30*60*1000); 
        try { 
            open(method, url, true); 
            if (method == 'POST') 
                setRequestHeader('Content-Type', 'application/x-www-form-urlencoded; charset=UTF-8'); 
            send(data); 
        } catch(e) {
            //alert(e.message);
        } 
        // on ready 
        onreadystatechange = function() { 
            if (objXMLHttpRequest.readyState == 4) { 
                callback(objXMLHttpRequest.responseText, objXMLHttpRequest.status); 
                delete(objXMLHttpRequest); 
            } 
        } 
    } 
}