var ajax = new AjaxObj(url); ajax.addListener(200, function(r){ alert(r); }); ajax.send();

var ajax = new AjaxObj(url).addListener(200, function(r){ alert(r); }).send();

AjaxObj = function(url, method, content){     this.r = null;     this.url = url;     this.method = method;     this.content = content;     this.header = {};     this.header["Connection"] = "close";     this.header["Content-type"] = "application/x-www-form-urlencoded";     var self = this;     if(window.XMLHttpRequest){         this.r = new XMLHttpRequest();     }else if(window.ActiveXObject){         try {             this.r = new ActiveXObject("Msxml2.XMLHTTP");         } catch(e) {             try{                 this.r = new ActiveXObject("Microsoft.XMLHTTP");             } catch(e) {             }         }     }     this.addListener = function(http_status, func){         if(!this.L)             this.L=[];         this.L[http_status] = func;         return this;     };     this.setHeader = function(name, value){         this.header[name] = value;         this.r.setRequestHeader(name, value);         return this;     };     this.send = function(){         if(this.method != "post" && this.method != "get")             this.method = "get";         this.r.open(this.method, this.url, true);         for(var h in this.header) {             this.r.setRequestHeader(h, this.header[h]);         }         this.r.send(this.content);     };     if(this.r) this.r.onreadystatechange = function(){         if(self.r.readyState == 4 && self.L[self.r.status] != null)             self.L[self.r.status](self.r.responseText);     }; };