An in-depth walkthrough is a bit too much, but here's a general process description:
1. Create a Profile property of type DateTime
2. Handle the LoggedIn event of the Login control
3. Create an instance of the Profile using Profile.Create and pass in the User Name of the Login control
4. Use DateTime.Compare (http://msdn.microsoft.com/en-us/libr...e.compare.aspx
) and see if the user account has expired
5. Redirect if necessary.
You'll find more information and examples of the various events, controls and properties on the MSDN web site.
Hope this helps,