session cookie timeout

[monotreme]

I'm bleary eyed reading vb core_functions code. You log into vbulletin so then you are idle for longer than the session cookie timeout option is configured for. Next time you come back and try to go to another page...... poof your logged out. I found where it checks this and sets up an update for shutdown. It must set the internal var $bbuserinfo['userid'] so that the templates do the right thing on the next pagefetch but I haven't seen where this happens. If I include some vb backend in my own code WHAT DO I POLL that will always tell me whether the vb user is logged in or not!! thank you