异步调用Web Service和页面中的类方法(出问题了。欢迎解决)

WebService:

using System;
using System.Web;
using System.Collections;
using System.Web.Services;
using System.Web.Services.Protocols;
using System.Web.Script.Services;

namespace WebApplication1
{
    /// <summary>
    /// WebService1 的摘要说明
    /// </summary>
    [WebService(Namespace = "http://tempuri.org/")]
    [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
    [System.ComponentModel.ToolboxItem(false)]
    // 若要允许使用 ASP.NET AJAX 从脚本中调用此 Web 服务，请取消对下行的注释。
    // [System.Web.Script.Services.ScriptService]
    [ScriptService]
    public class WebService1 : System.Web.Services.WebService
    {

        //[WebMethod]
        //public string HelloWorld()
        //{
        //    return "Hello World";
        //}

         [WebMethod]
        public string[] GetNews()
        {
            string[] arrNews = new string[3];
            arrNews[0] = "新闻联播";
            arrNews[1] = "焦点访谈";
            arrNews[2] = "快乐大风车";

            return arrNews;

        }
    }
}

前台：<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="WebApplication1.WebForm1" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
    <script type="text/javascript">
        var myselect;
        window.onload = function () {
            myselect = $get("myselect");
            WebService1.GetNews(onSuccessed, onFailed);
        }
        function onSuccessed(result) {
            for (var i = 0; i < result.length; i++) {
                var opt = new Option();
                opt.value = i;
                opt.text = result[i];
                myselect.options.add(opt);
            }
        }
        function onFailed(err) {
            alert(err.message);
        }

    </script>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:ScriptManager ID="ScriptManager1" runat="server">
            <Services>
            <asp:ServiceReference  Path="~/WebService1.asmx" />
            </Services>

        </asp:ScriptManager>
        <select id="myselect">
        </select>
    </div>
    </form>
</body>
</html>

问题： 'WebService1' 未定义，找不到WebService1 文件 --------------------编程问答-------------------- // [System.Web.Script.Services.ScriptService]


这句话要把他取消注释
在编译下再看下行不 --------------------编程问答-------------------- 微软的示例，ajax调用webservice
http://msdn.microsoft.com/zh-cn/magazine/cc163499.aspx

补充：.NET技术 ,  Web Services