modalpopupextender with frameset

[bzeng]

Hi

I have a typical frameset page (Default.aspx) that separate the page into Top, Left and Main. I want to add modalpopupextender on the frameset page so that the popup covers the WHOLE SCREEN.

------------- Default.aspx file ---------------

<form id="form1" runat="server">
<div>
<div style="display: none">
<asp:button id="btnPopup" cssclass="ms-button" runat="server" />
</div>
<asp:toolkitscriptmanager id="ScriptManager1" runat="server">
</asp:toolkitscriptmanager>
<asp:panel id="Panel1" runat="server" style="display: none" cssclass="modalPopup">
some text here.
<asp:Button ID="btnClose" runat="server" Text="Close" OnClick="btnClose_Click" />
</asp:panel>
<asp:modalpopupextender id="Panel1_ModalPopupExtender" runat="server" dynamicservicepath=""
enabled="True" targetcontrolid="btnPopup" popupcontrolid="Panel1" backgroundcssclass="modalBackground">
</asp:modalpopupextender>
</div>
</form>

<frameset rows="86,*" frameborder="0" border="0" framespacing="0">
<frame name="Top" scrolling="no" src="Top.aspx" frameborder="0" marginheight="0" marginwidth="0" />
<frameset id="frame" cols="150,*" frameborder="0">
<frame name="Left" frameborder="0" noresize scrolling="no" src="Left.aspx?ParentID=1" />
<frame name="Main" scrolling="yes" src="Blank.aspx" />
</frameset>
<noframes>
</noframes>
</frameset>

------------ Default.aspx.cs --------------

protected void Page_Load(object sender, EventArgs e)
{
this.Panel1_ModalPopupExtender.Show();
}

protected void btnClose_Click(object sender, EventArgs e)
{
this.Panel1_ModalPopupExtender.Dispose();
}



It shows the modalpopup when the page loads, but the frameset does not showup.

The backgroundcssclass="modalBackground" is transparent so I should be able to see the frameset behinde the popup. But there is nothing behind and if I click the Close button on the pop, it return to a blank page.

How can I make the modalpopup to work on a typical frameset page?

Thanks in advance!