[kh99]

Where did you put your code for creating a forum? If you are already including vbulletin's global.php, or if you are writing a plugin, then you probably don't have to explicitly include anything. If this is a custom script that doesn't include vbulletin's global.php then that's more of a problem. In that case it may turn out to be too difficult to use any vbulletin code since it mostly depends on having included global.php, which has a lot of overhead associate with it.

ETA: OK, I see you said above that you're creating a custom page. So if you're not already including vbulletin global.php then you'd have to think about adding it if you want to use the above code.