function Ajax(obj) {
   if(obj.method.toUpperCase() == "GET") {
   this.get(obj.url,obj.postData,obj.dataType,{success:obj.success,fail:obj.fail},obj.async);            } else if (obj.method.toUpperCase() == "POST"){
   this.post(obj.url,obj.postData,obj.dataType,{success:obj.success,fail:obj.fail},obj.async);            } else {
   this.get(obj.url,obj.postData,obj.dataType,{success:obj.success,fail:obj.fail},obj.async);            } } Ajax.prototype = {
       xhr: (function(){
   var xhr = null; try {
               xhr = new XMLHttpRequest();         } catch (e) {
   try {
                   xhr = new XMLHttpRequest("Msxml2.XMLHTTP");                    } catch (e) {
                  xhr  = new ActiveXObject("Microsoft.XMLHTTP");                             }         } return xhr;     })(),     post: function(url,data,dataType,callback,async) {
   var _xhr = this.xhr;         _xhr.open("POST", url, async);             _xhr.setRequestHeader("Content-Type","application/x-www-form-urlencoded");         _xhr.send(data); this.handle(_xhr,dataType,callback);     },     get: function(url,data,dataType,callback,async) {
   var _xhr = this.xhr;         _xhr .open("GET",url,async);         _xhr.send(null); this.handle(_xhr,dataType,callback);     },     handle: function(_xhr,dataType,callback) {
   var _dataType = dataType.toUpperCase();         _xhr.onreadystatechange = function() {
   if (_xhr.readyState == 4) {
   if (_xhr.status == 200) {
   var _data = (_dataType =="XML" ? _xhr.responseXML : _dataType == "JSON"  ? (new Function("","return "+_xhr.responseText))() : _xhr.responseText);                     callback.success(_data);                 } else {
   var _data = (_dataType =="XML" ? _xhr.responseXML : _dataType == "JSON"  ? (new Function("","return "+_xhr.responseText))() : _xhr.responseText);                     callback.fail(_data);                                        }             }         }     } }

new Ajax({
       url:"http://localhost:8080/hsdj/getUserPower.hebe",     postData:'',     dataType:"json",     async:"true",     success:function(data){
   for(var i in data) {
               alert(data);         }     },     fail:function(data){
       },     method:"POST" });