ajax发送多个跨域请求回调不混乱

     var count = 0;
     var codes = "";
     function refreshCache(urls){
         try {
             var url = urls.split(",");
             if(url.length <=0){
                 alert("刷新失败，请配置刷新地址！");
                 return;
             }
             count = 0;
             refesh(url);
        }catch(err){
            alert("请求失败。");
        }
     } 

  function refesh(url){
         var u = url[count];
         console.log("第"+count+"个"+u);
         $.ajax({
             url : u,
             type : 'POST',
             dataType: "jsonp",
             timeout: 2000,
             cache:false,
             async:false,
             jsonpCallback: "jsonpcallback",
             success : function(data, status, xhr) {
                 console.log(u+"回调被执行了... 参数为："+data);
                 if(data == '0000'){
                     console.log(u+"回调执行成功");
                     count++;
                     if(count <20 && count < url.length){
                         refesh(url);
                     }
                 }else{
                     console.log(u+"回调执行失败");
                     alert("刷新失败，请稍后再试");
                 }
             },
             error : function(xhr, error, exception) {
                 alert("请求失败。");
             }
         });
 　　}