How to have a div fill horizontal space to the left and right of a fixed width div

[sochedoff]

I have 3 div's: \[code\]divLeft\[/code\], \[code\]divCenter\[/code\] and \[code\]divRight\[/code\] and I want \[code\]divCenter\[/code\] to be centered with a width of 1200px. The left and the right should have fluid width to fill up to the edge of the screen.How can I do this?