安装的是2.0的AJAX框架，添加的是2.0的AjaxControlToolkit.dll的引用，可是在页面拉控件的时候，老是出现这样的错误!
页面代码：
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>
<%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="cc1" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<asp:ScriptManager ID="ScriptManager1" runat="server" />
<div>
<cc1:Accordion ID="Accordion1" runat="server" Height="154px" Width="202px">
<Panes>
<cc1:AccordionPane ID="AccordionPane1" runat="server">
<Header>
你好....
</Header>
<Content>
