CSS - layering background images

Hi I was wondering if someone could help me sort out what I think could be a simple problem.

I am using a background image on my site which I want to then layer 2 gif images on top of:

one gif image has to repeat for the entire page as the background image (no i cant include this on the original background image, it MUST be a separate element)

and the other image must be centered on top of these two images. the only site i have noticed to date with something similar is this one http://bockmantheband.com

I am new to CSS and the containers looks a bit complex, any help on the css would be great.

Feel free to ask more questions if i have not made myself clear