Problems with div covering browser window

Problems with div covering browser window

I asked a question on here earlier, and the responses I got were great.
I've created this
http://jsfiddle.net/wCZYU/5/
<header class="pageHeader">
<div class="setWidth">
<a href="index.php" class="logoImg"></a>
<div class="navMain">
<a href="index.php">Home</a>
<a href="portfolio.php">Work</a>
<a href="/blog">Blog</a>
<a href="contact.php">Contact</a>
</div>
</div>
</header>
<div class="content"></div>
I'm trying to get the content which is behind the nav, to come below it,
surely there must be another way to do it without margin/padding? I just
need a little more help. I still want the light grey div to cover the
entire browser window however. It must also work for IE
Thanks again