AJAX ScriptManagerProxy调用webservice

内容页：
<%@ Page Title="" Language="C#" MasterPageFile="~/Site1.Master" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="ScriptManagerProxyDemo.WebForm1" %>
<asp:Content ID="Content1" ContentPlaceHolderID="ContentPlaceHolder1" runat="server">
<script type="text/javascript">
    function EchoUserInput() {
        var echoElem = $get("EnteredValue");
        alert(echoElem);
        ScriptManagerProxyDemo.WebService1.EchoInput(echoElem.value, OnSucceeded);
    }
    function OnSucceeded(result)
    {
        var RsltElem = $get("Results");
       
        RsltElem.innerHTML=result;
    }
</script>
    <asp:ScriptManagerProxy ID="ScriptManagerProxy1" runat="server">
        <Services>
            <asp:ServiceReference Path="~/WebService1.asmx" />
        </Services>
    </asp:ScriptManagerProxy>
    <input type="text" id="EnteredValue" /><input type="button"  onclick="EchoUserInput()"/>
    <div id="Results"></div>
   
</asp:Content>
webservice：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Services;
namespace ScriptManagerProxyDemo
{
    /// <summary>
    /// WebService1 的摘要说明
    /// </summary>
    [WebService(Namespace = "http://tempuri.org/")]
    [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile