Set the DefaultButton of a Panel at runtime

Hi,
Is there's a solution for the problem that I'm facing too in this article : http://p2p.wrox.com/topic.asp?TOPIC_ID=45587 ?
Or even simpler : How can I make this code work in a user control inside a masterpage ?
 
User Control :
 
<asp:Panel ID="i_pnlFvInformations" runat="server" BorderColor="#ff0000" BorderStyle="Solid" BorderWidth="2px">
    <br />
    <br />
    <br />
    <br />
    <asp:Label ID="i_lbl" runat="server"></asp:Label>
    <asp:Button ID="Button1" runat="server" Text="Button" OnClick="Button1_Click" />
& ...