CSS borders in 3 col layout

[mgm_03]

I am on a mac using Firefox. example

Trying to position the center image (452px wide) so that there is 4px border on either side (left and right cols are 150px each) total page width 760px. All of my ideas have failed.

I spend hours trying to get CSS to work after having read books from SitePoint and elsewhere. Ultimately, I raise the white flag and post here only to find out a hack is required. Using tables for layout may not be semantically correct but they get the job done with minimal angst. ..end of rant.

Advice is appreciated. (i know the design sucks).