<html>
<head>
<style>
div.box {
  height: 100px;
  background-color:green;
  display: -moz-box;
  display: -webkit-box;
  display: box;
}

</style>
</head>
<body>
You should see a green rectangle below that is 100 pixels tall and that fills the width of the content area.  If you see any red, then the test has failed.  

<div style="background-color:red;height:100px">
<div class="box"></div></div></div>
</body>
</html>