关于AJAX控件ModalPopupExtender的疑问

[hbbdhbbd]

web窗体中有两个panel：panel1和panel2，在panel1中有个button按钮ID：btnClick，我想在点击btnClick时弹出一个对话框，为panel2的内容，所以想用ModalPopupExtender控件，于是在panel1增加前台代码如下：
<cc1:ModalPopupExtender ID="ModalPopupExtender1" runat="server" TargetControlID = "btnClick" PopupControlID ="panel2" >
</cc1:ModalPopupExtender>
但是运行出错，我不太会用这个控件请问高手该怎样设置

[hbbdhbbd]

up

[E_wait]

<asp:Button runat="server" ID="hiddenTargetControlForEwaitModalPopup"/>
<asp:Panel ID="pnlEwait" runat="server" Style="display: none; width: 250px;" CssClass="modalPopup">
<asp:Panel ID="pnlEwaitHandle" runat="server" class="PopupHandle">
<table width="100%">
<tr>
<td style="width: 230px; text-align: center; font-size: 12px; font-weight: bold">
标头
</td>
<td style="text-align: right; vertical-align: top; font-size: 10px;">
<a id="Ewaitpopupclose">
<img src="/images/btn_close.gif" alt="关闭" /></a>
</td>
</tr>
</table>
</asp:Panel>
<div>

</div>
</asp:Panel>
<cc1:ModalPopupExtender runat="server" ID="EwaitModalPopupExtender" ="TargetControlIDhiddenTargetControlForEwaitModalPopup"
CancelControlID="Ewaitpopupclose" BehaviorID="EwaitModalPopupBehavior" PopupControlID="pnlEwait"
BackgroundCssClass="modalBackground" DropShadow="True" PopupDragHandleControlID="pnlEwaitHandle"
RepositionMode="RepositionOnWindowScroll">
</cc1:ModalPopupExtender>

到http://www.asp.net/ajax/ajaxcontroltoolkit/samples/这里看看吧,里面有详细介绍每个控件的具体用法,各个属性的作用

[E_wait]

红色的写错了.应该是TargetControlID="hiddenTargetControlForEwaitModalPopup"