Merging with existing user database

[DanClark]

Hi,

I have a website with a user database. The website has some content viewable to the general public, other content requires a user to log in.

I want to use vBulletin forums, but don't want my users to have to log into the site, then have to log into the forums also.

My question: is it possible to merge my existing user database into the vBulletiin db so that when a user logs into my site, they are also logged into the vBulletin forums and can post there without the need to log in again.

I know this would require me to create a vBulletin user account when a new user registered to my site (and also creating user accounts for all existing users), but how about telling vBulletin they are already logged in? Would it be a case of generating the sessions for vBulletin?

Has anyone done this before or have any idea where to start.

Thanks for your time and help!

Dan