CSS Full Background

There are several ways to do this, this blog post have an excellent explanation

Perfect Full Background Image

Since I’m a lazy potatogrammer, I’ll use CSS 3 for the trick

html {
	background: url(img/background.jpg) repeat center center fixed;
	-webkit-background-size: cover;
	-moz-background-size: cover;
	-o-background-size: cover;
	background-size: cover;
}