.content {
	position: relative;
	width: 760px;
	z-index: 10;
}
.background {
	top: 0;
	left: 0;
	width: 100%;
	height: 100%;
	position: absolute;
	z-index:2;
}
.portrait {
	height: 100%;
}
.landscape {
	width: 100%;
}
.full {
	width: 100%;
	height: 100%;
}

http://www.1stwebdesigner.com/css/17-css-html-effects/

HTML should look like this:

<div>
	<p>Lorem ipsum here</p>
</div>
<div>
	<img>
</div>

Full-screen background (IE included)

ie, background

CSS