Forms authentication with multiple projects in a solution

[Steven J. Reed]

I am attempting to break my application into multiple projects using the
technique described in KB #307467.

I successfully execute my 'Main' project, login based upon Form
authentication, and click a link to my 'Sub' project. However, when I
redirect from my 'Main' project to the 'Sub' project (Response.Redirect
"Sub/subpage.aspx"), I get the error "The resource cannot be found" with the
Requested URL being Main/Sub/frmLogin.aspx.

If I create a web.config in my Sub project and create an authorization form,
all the session variable are gone, implying that a new session has been
started.

How can I switch to my sub projects and have all my session info available
to me?