UpdatePane刷新和Ajax控件Timer的问题，刷新没有效果，解决方法

拉了一个ScriptManager 在拉UpdatePane 在UpdatePane里面放一个Ajax控件Timer，设置时间间隔1000，在放个Label1 ，页面代码为：

<%@ Page Language="C#" AutoEventWireup="true"  CodeFile="Default.aspx.cs" Inherits="_Default" %>

<%@ Register Assembly="System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"
    Namespace="System.Web.UI" TagPrefix="asp" %>


<!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>无标题页</title>
</head>
<body>
    <form id="form1" runat="server">
        <asp:ScriptManager id="ScriptManager1" runat="server">
        </asp:ScriptManager>
        <asp:UpdatePanel id="UpdatePanel1" runat="server">
            <contenttemplate><asp:Label id="Label1" runat="server" Text="Label"></asp:Label>
<asp:Timer id="Timer1" runat="server" OnTick="Timer1_Tick" Interval="1000"></asp:Timer> 
</contenttemplate>
        </asp:UpdatePanel>
      
      
    </form>
</body>
</html>

后台代码为：

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Web.Services.Description;

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

    protected void Timer1_Tick(object sender, EventArgs e)
    {
        
        this.Label1.Text = DateTime.Now.ToString();
    }
}

问题解决了原来是要在在web.config中的system.web配置节中添加

<httpHandlers>
 <add verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" validate="false"/>
</httpHandlers>