Single Sign On?

[toonysnn]

I'm not entirely sure how your code works, but as far as vBulletin goes, it's as easy as including a file and checking if a member is signed on, or a guest. ($show['member'] would help greatly in this situation.)

If you happen to purchase vBulletin, I (amongst many others) should be able to help you accomplish what you need, and the numerous amount of articles here should help as well. I assume by "The rest of the site uses the forum's login," you mean you redirect some sort of login URL to the forum dedicated login page? (seeing as SMF and such have those)