Владимир Грабко

var request = getXmlHttp();
                request.open('GET', url, true);

                request.onreadystatechange = function () {
                    if (this.readyState === 4) {
                        if (this.status >= 200 && this.status < 400) {
                            eval(this.responseText);
                            call();
                        }
                    }
                };

                request.send();
                request = null;