help changing background color to image in SMF forum

I'm trying to put an image as the background instead of just a color. What do I need to add to the CSS file and what size should the image be?
Thanks in advance.

 

Pretty easy.
I would show you exactly how the code should look, but you didn't post the CSS coding.
Anyways. Try this:

background-image:url('yourimage.png');

Code (markup):

 

lol, ya i got it. It was a little more then that but I got it.
Thanks man.