I wrote a service that used the sessionId ( from memory ) to copy the session variables between ASP and ASP.NET. That worked well. Your core issue is, anything you can't pass on the URL, your two projects won't be able to share, by default. I believe I passed the ID to ASP.NET on the URL, which it used to get session variables from the service. Obviously, the asp app had to stuff them in as well.
Christian Graus - C++ MVP 'Why don't we jump on a fad that hasn't already been widely discredited ?' - Dilbert