[Lynne]

So a certain user can't see the page?

PHP Code:

if ($vbulletin->userinfo['userid'] == x)
{
    print_no_permission();
} 


So no unregisitered users can see the page:

PHP Code:

if (!isset($vbulletin->userinfo['userid']) OR $vbulletin->userinfo['userid'] == 0)
{
    print_no_permission();
}