[themes] changing page template based on node type from within template.php

Hi folks,

I'm trying to serve a specific page template for all nodes that are forum posts.

As of right now, I've been twiddling in template.php to do similar work... serve different templates based on url arg().

Here's the function I'm using: http://pastebin.com/767797

Note that I've been trying to grab the node type /(if (arg(0) == 'node' && is_numeric(arg(1)))/ and then trying to load a page template based on that: /elseif ($node->type == 'forum') {/

I thought this was the proper way to do this, yet now I'm getting some scary looking mySQL errors (linked so I don't have to paste them in here): http://qatotonetwork.newmbc.com/node/1110

Would appreciate some help if anyone has a clue what I'm doing wrong here. Thanks in advance!

-John