How to use external session for authorization of members?

[Martin Belak]

Hi guys, I'm struggling with an integration problem an would need some help from all vB-experts on this board.

This is the issue:
I have a website with it's own user-database and session based authorisation system. The site need a discussion board. We would therefore like to hook up vB to the site. The idea is to create an vB user automatically when a new member sign up at the main site. That's the easy part. The harder one is the login process. We don't want two separate login procedures. The ideal way would be to modify the authorisation functions in vB and let the board use the same login session as the main site.

So my questions are:
-Is this possible to do with vB?
-In wich include file can I find the authorisation function?
-Can anybody help me?

Best,
/M