Little background problem...?!

I'm currently working on my second forum to tweak/hack/edit it but now i got a whole new problem. The problem is that i want to add a background with rounds, its a bit hard to explain for me since my english isn't that good.

maybe a screenshot will help you to see what i mean:
http://www.pcgnetworks.com/example.gif < here you see the difference a light blue cornered background arround the threads/forum display etc... (needs to show up on every page)

and to see how im doing and still trying to add those rounds somewhere, somehow, http://forums.pcgnetworks.com but < as you can see just a flat line over there and no nice cornered background (yet)

maybe someone knows how to do this, saw it before on some forums, but i can't find it.

any help is appreciated!!

(edit: little note: this example forum is under major construction hehehehe)

[Dean C]

I'm sorry i don't understand buddy

- miSt

[_Mr_CLuBBeR_]

Hmm thats weird lol.

ok second try: header -> light blue > white line > dark blue> then begins the light blue again (bit darker) and got corners in the example image, now if you click on the forum link you'll see its not there (yet).

understand it now maybe ?

[_Mr_CLuBBeR_]

well nevermind! i found it out myself after like 30 minutes i had apparently a clear moment in my mind :P http://forums.pcgnetworks.com << now you see what i mean? the corners in the background??