<html>
<head>
<style>
body {
  height: 40px;
  -moz-column-count: 2;
}
#x {
  height: 20px;
}
#y {
  height: 80px;
}
</style>

<script>
function boom()
{
  document.getElementById("x").style.content = "'0'";
}
</script>
</head>

<body onload="boom();"><div id="x"><div id="y"></div></div></body>

</html>