handler

(function(open, send) {

    XMLHttpRequest.prototype.open = function(method, url, async, user, pass) {

        this.addEventListener("readystatechange", function() {
            if(this.readyState === 4 {

              // code


            }
        }, false);

        open.call(this, method, url, async, user, pass);
    };

    XMLHttpRequest.prototype.send = function(params) {

        send.call(this, params);
    }

})(XMLHttpRequest.prototype.open, XMLHttpRequest.prototype.send);