jq中的ajax的返回值怎么接收啊？

<script type="text/javascript">
            $(document).ready(function () {
                $("#Llogin").click(function () {
                    $.ajax({
                        type: "post",
                        url: "../Ashx/login.ashx/Getjieguo",
                        datatype: "json",
                        contentType: "application/json; charset=utf-8",
                        success: function (data) {
                            alert(data);
                        }
                    });
                });
            });
        </script>

login.ashx页面：

[WebMethod]
    public static string Getjieguo()
    {
        return "实验！";
    }

为什么返回的结果永远是空呢？求指点！ ajax ASP.NET C#
[解决办法]
using System;
using System.Web;
using System.Web.Services;
using System.Data;
using System.Web.SessionState;

public class login : IHttpHandler, IRequiresSessionState
{

public void ProcessRequest(HttpContext context)
{

string ss = "实验！";
context.Response.Write(ss);
context.Response.End();
}

public bool IsReusable
{
get
{
return false;
}
}
[WebMethod]
public static string Getjieguo()
{
}

}