Problem with the background image

[Ninja]

I have a problem.
I have been doing my homepages using Photoshop.
Now I have done a good backround but it's bit difficult to code.
Let's look. The layout of my site is quite similar like this: http://i14.tinypic.com/6310qz9.jpg
So that white area is the contents. I want to use grids, gradient colour and even shadows.
I use dividers. How should I code?

I mean HOW I can do slices?
Yes, in Photoshop (or Image Ready) but how that background should be coded?
The grids and the gradient colour are the biggest problems because the background doesn't repeat in the right way. I don't know what kind of piece I should take from the image and how I have to code it.
I want to use dividers and CSS. So shortly: How do I have to make slices that the background repeats in the right way?

[CopperDesk]

You can't tile this background.

First, why we tile a image... to keep the file size small...

use it as a single image... compress well. That will solve the purpose i think.

[Ninja]

I'm sorry but I don't understand - completely.

The width of my layout is 870 pixels + shadows.
I mean how I can just tile that image and it will work.