Postback problem when PopupExtender is placed inside a user control
<p>I am creating a ModalPopupExtender inside a Web User Control.
When i click on the OK Button in the panel, which is showing as model popup, the Event Handeler of the button is not executing.
This problen does not occure when i do not use the Web User Control.
Here is the user control (.ascx) file code.</p>

<pre><code>&lt;script type="text/javascript" language="javascript"&gt;
    function OkClicked(sender, e) {
            __doPostBack('Button1', e);
        }
&lt;/script&gt;

&lt;asp:Button ID="Button2" runat="server" Text="Show" /&gt;
&lt;asp:Panel ID="Panel1" runat="server"&gt;
    &lt;asp:TextBox ID="TextBox1" runat="server"&gt;&lt;/asp:TextBox&gt;
    &lt;asp:Button ID="Button1" runat="server" Text="Button" onclick="Button1_Click" /&gt;
&lt;/asp:Panel&gt;
&lt;asp:ModalPopupExtender ID="ModalPopupExtender1" runat="server" 
    DropShadow="True" OkControlID="Button1" PopupControlID="Panel1" 
    TargetControlID="Button2" onokscript="OkClicked()"&gt;
&lt;/asp:ModalPopupExtender&gt;        
&lt;p&gt;
    &lt;asp:Label ID="Label1" runat="server" Text="Label"&gt;&lt;/asp:Label&gt;
&lt;/p&gt;
</code></pre>

<p>And the Event Handeler for the click event of the 'Button1' is </p>

<pre><code>protected void Button1_Click(object sender, EventArgs e)
{
    Label1.Text = TextBox1.Text;
}
</code></pre>
