Jquery ajax响应在IE 8中未定义但在其他浏览器中工作

Question

$.ajax({
    url: "FetchApplicationList",
    async: true,
    type: "GET",
    success: function (result) {
        alert(result); // this is giving undefined in IE but working fine in firefox and chorme

        $(result).find('app').each(function () {
            appList.push($(this).find('appName').text());
        });
    },
    error: function (e) {
        alert(e.message);
    }
});