jquery ajax ashx返回值替空求解

function funStateJudge() {
    $.ajax({
        url: "Service/PassWordJudge.asmx/StateJudge",
        contentType: "application/json",
        dataType: "json",
        data: "{}",
        type: "POST",
        success: function (json) {
            //alert(json.d);//输出结果
            if (json.d == "1") {
                document.getElementById("divState").style.visibility = "visible";
                funGetUserData(); //显示获取登陆信息
            }
            else {
                funShowpnlLogin();
                document.getElementById("divState").style.visibility = "hidden";
            }
        },
        error: function (x, e) {
            alert(x.responseText);
            errorSolve(); //异常处理
        }
    });
}

function funGetUserData() {
    $.ajax({
        url: "Service/GetSessionValue.ashx",
        contentType: "application/json",
        dataType: "json",
        type: "POST",
        data: "{}",
        success: function (json) {
            //             alert(json.UserName); //输出结果
            //             alert(json.UserAccount); //输出结果
            document.getElementById("lbtnUserName").innerText = json.UserName; //显示输出用户姓名
            document.getElementById("lbtnUserAccount").innerText = json.UserAccount; //显示输出用户帐号
        },
        error: function (x, e) {
            funGetUserData(); //重复调用，方式页面加载时调用失败{这里两个页面之间来回跳转时无规律的出现失败现象，返回结果为空，反复调用即可得到返回值。。求解}
        }
    });
}

        public void ProcessRequest(HttpContext context)
        {
            context.Response.ContentType = "text/plain";

            string strData = String.Format("{{UserName:\"{0}\",UserAccount:\"{1}\"}}", getUserName(), getUserAccount());//构建的json数据

            //下面两句是用来测试前台向此页面发出的查询字符

            context.Response.Write(strData);



        }