hook throws an error

[lukemax]

I'm trying to show a php table only when a certain forum is displayed, so I inserted the php code into a plugin and am having trouble whenever I enable the hook.
(attachment #1) The error
(attachment #2) The hook
(attachment #3) the if statement in the FORUMDISPLAY template to display code only when its equal to 6.
Any ideas???
hook (http://www.lvasp.com/providers_hook.php Nothing explicit, just model shots, but just to be safe, ADULTS ONLY!~!)