ScriptManager 发送错误到客户端

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="WebApplication4.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>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    <%--AllowCustomErrorsRedirect属性设置为false，配合后台的自定义错误使用--%>  
            <asp:ScriptManager ID="ScriptManager1" runat="server" AllowCustomErrorsRedirect="false" OnAsyncPostBackError="ScriptManager1_AsyncPostBackError">  
            </asp:ScriptManager>  
      
            <asp:UpdatePanel ID="UpdatePanel1" runat="server">  
                <ContentTemplate>  
                    <asp:Button ID="Button1" runat="server" Text="Button" OnClick="Button1_Click" />  
                </ContentTemplate>  
            </asp:UpdatePanel>  
              
            <%--自定义错误处理--%>  
            <div id="error"></div>  
              
            <script type="text/javascript" language="javascript">  
                Sys.WebForms.PageRequestManager.getInstance().add_endRequest(function(sender, e)  
                {  
                    e.set_errorHandled(true);  
                    //将信息显示到上面的div区块中innerHTML，这里可以设置默认的错误信息  
                    $get("error").innerHTML = "Sorry, an error has occurred: " + e.get_error().message;  
                    setTimeout(function(){ $get("error").innerHTML = ""; }, 3000);//3秒后变为空  
                });  
            </script>  

    </div>
    </form>
</body>
</html>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace WebApplication4
{
    public partial class WebForm1 : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {

        }

        protected void Button1_Click(object sender, EventArgs e)
        {
            //自定义错误处理，配合web.config文件中的错误配置节点customErrors（设置为on的时候才生效，同时还要制定错误页）和AllowCustomErrorsRedirect（是否允许customErrors）使用  
            throw new Exception("错误信息提示!");  

        }

        protected void ScriptManager1_AsyncPostBackError(object sender, AsyncPostBackErrorEventArgs e)
        {
            ScriptManager.GetCurrent(this).AsyncPostBackErrorMessage = e.Exception.Message; 
        }
    }
}