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

div.innerBox {
  width: 100px;
  background-color:green;
}
</style>
</head>
<body>
<p>You should see a green 100x100 box below.  If you see a red box, then the inner block is not properly growing
to fill the height of the enclosing box.
</p>
<div class="box">
<div class="innerbox"></div>
</div>
</div>
</body>
</html>