Why is my div not horizontally centered?

Question

I have two divs horizontally aligned next to each other, each taking ~50% of the page width. Now if the browser window changes, my I want to keep one div centered (<div id="featured">) but it doesn't, even tho I set margin: 0 auto;) How can I keep it centered in its area (right side of the 50%)? link: http://spabc.com/drupal

Answer 1

Or if you want the images right next to the div on the left you can position absolute it and then use margin left on the images. Hope this helps.