title: Center a div in a section
body: <p>I'm trying to center a <code>&lt;div&gt;</code> in <code>&lt;section&gt;</code>. Setting margin-left and margin-right to <code>auto</code> isn't working (my usual method). What am I forgetting?</p>
  
  <p>jsFiddle of the problem: <a href="http://jsfiddle.net/veWKh/" rel="nofollow">http://jsfiddle.net/veWKh/</a></p>