<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0//EN">
<html lang="en">
 <head>
  <title>Margin Collapsing: negative margins (easy)</title>
  <style type="text/css">
  #container { background: red; width: 5em; height: 2em; }
  #control { background: blue; width: 5em; height: 1em; margin-bottom: 1em; }
  #test { background: yellow; width: 5em; height: 1em; margin-top: -1em; display: block; }
  </style>
 </head>
 <body>
  <p>There should be no red below.</p>
  <div id="container">
    <div id="control"></div>
    <img id="test">
  </div>
 </body>
</html>