<!DOCTYPE html>
<html>
<head>
<script type='text/javascript'>
window.addEvent('load', function() {
element = document.getElementById('abc');
element.innerHTML = "<div class='a'>Some other contents here </div>" + element.innerHTML;
});
</script>
</head>
<body>
<div id='abc'>
<div class='a'>Some contents here</div>
<div class='b'>Some other contents</div>
</div>
</body>
</html>