<p>I have a Button inside an UpdatePanel.  The button is being used as the OK button for a ModalPopupExtender.  For some reason, the button click event is not firing.  Any ideas?  Am I missing something?</p>

<pre><code>&lt;asp:updatepanel id="UpdatePanel1" runat="server"&gt;
    &lt;ContentTemplate&gt;
        &lt;cc1:ModalPopupExtender ID="ModalDialog" runat="server" 
            TargetControlID="OpenDialogLinkButton"
            PopupControlID="ModalDialogPanel" OkControlID="ModalOKButton"
            BackgroundCssClass="ModalBackground"&gt;
        &lt;/cc1:ModalPopupExtender&gt;
        &lt;asp:Panel ID="ModalDialogPanel" CssClass="ModalPopup" runat="server"&gt;
            ...
            &lt;asp:Button ID="ModalOKButton" runat="server" Text="OK" 
                        onclick="ModalOKButton_Click" /&gt;
        &lt;/asp:Panel&gt;
    &lt;/ContentTemplate&gt;
&lt;/asp:updatepanel&gt;
</code></pre>

It appears that a button that is used as the OK or CANCEL button for a ModalPopupExtender cannot have a click event.  I tested this out by removing the
```
```
OkControlID="ModalOKButton"
```
```
from the ModalPopupExtender tag, and the button click fires.  I'll need to figure out another way to send the data to the server.