Good day, not sure what to do.

I have an ascx page with the code displaying the user logged in, i created an iframe src displaying a report but i want to add the logged in id as parameter but can't determine the code value.

ascx page code
Code:
<%@ Control Language="c#" AutoEventWireup="True" Codebehind="Header.ascx.cs" Inherits="FlowCentric.Net.Navigator.Header" TargetSchema="http://schemas.microsoft.com/intellisense/ie5"%>
<tr>            
<td><asp:Label id="lblLogin" runat="server">Welcome</asp:Label></td>
 </tr>
the iframe report i add & add the user parameter to the label's lblLogon value.
Code:
 <IFRAME id="frame1" src="http://biweb/reportserver?&User=lblLogin"</IFRAME>
Please Assist, totally lost