wanting a fixed image on the right and left sides..

[talkncaasports]

Here is my website: http://www.olevetpossehideout.com/forums/index.php

I have the background set to what I want and it is fixed. However, I was wondering if there was a way to add a background image on the left and right sides without creating a new backbround image, since the current background is repeating.
How would I be able to do this?
Thanks in advance.

[Dismounted]

One method would be encasing the whole forum in a table (3 columns), and assigning the background to the middle cell. Then assign backgrounds on the right and left. However, this would mean the forum itself would have to be a fixed width.