    }
            };

            xhr.send(body);
        }

        function httpGet(url, params, successCallback, errorCallback) {
            url = url + "?" + params;

            let xhr = new XMLHttpRequest();
            xhr.onreadystatechange = function () {
                if (xhr.readyState === 4) {
                    if (xhr.status === 200) {
                        successCallback(xhr.responseText);
                    } else if (errorCallback != null) {
                        errorCallback(xh