[kh99]

If I'm following this correctly, I think the condition should be:

PHP Code:

// access permissions
if ((!is_member_of($vbulletin->userinfo, 5, 6, 7)) AND ((!isset($age)) OR ($age == '$nbsp;') OR ($age < 18)))
{
// give no permission unless in usergroup x, y, or z
        print_no_permission();
} 


I'm assuming that if age isn't set or it's set to nbsp that the user won't have permission.