how to use html5 tag for ie8 and 1e7

here is very simple script that allow to use html 5 tag for ie8 and ie7

<!--[if lt IE 9]>
<script>
document.createElement('header');
document.createElement('nav');
document.createElement('section');
document.createElement('article');
document.createElement('aside');
document.createElement('footer');
document.createElement('hgroup');
</script>
<![endif]-->