Centering your board without using CSS body center layout..?

Hi,

I am wondering how I center my forums board without having to do a margin count for the left side to center it only for 1024x768.

Where in the code do i center the forums page without using <center> </center> because that centers everything including the text.

Thanks

The site is

http://www.homedecorlighting.com/forum/index.php

Ryan