Integrate vbulletin with website

[paperboy741258]

I am trying to create a custom cms system similar to phpnuke or vbadvanced for my website. I am trying to get vbulletin to include in the middle of the site with a php include.

When I do the following, the include works just fine

test.php

PHP Code:

<?PHP 
include ('modules/forum/index.php');

however, I dont want to use test.php I would like to have the url be something similar to index.php?modules=forum. When I use the same code with the differant url I get the following error.

Fatal error: Call to a member function query_first_slave() on a non-object in [some path removed]Public_html\modules\forum\includes\functions.php on line 1270

Any Suggestions?