CSS - absolute positioning and fluid divs

I need to make a layout that looks like this:

[250px - fixed div]  [fluid div, must expand depending on the width of the body and the 2 divs next/before it]  [250px - fixed div]

is this possible? the container of all 3 divs is also fluid (100% width). all these divs contain background images (left + right + repeating center image) and should stay in the back.