html, body, #contents {
	min-height: 100%;
	width: 100%;
	height: 100%;
}

/*
 * The "height" above is a hack for IE5+/Win.  Below we adjust
 * it using the child selector to hide from IE5+/Win
 */

html>body, html>body #contents {
	height: auto;
}

/*
 * Without this, Moz1.0 adds a vertical scrollbar
 */

body {
	margin: 0;
	font-family: Arial, sans-serif;
}

#contents {
	position: absolute;
	top: 0;
    left: 0;
/*  Use the following to center this at 50% width, or this for 750px: width: 700px, margin-left: -350px: */
/*
	left: 50%;
    width: 50%;
    margin-left: -25%;
*/
}

#footer {
	position: absolute;
	bottom: 0;
	background-color: #ccffcc;
	width: 70%; /* See note below */
	text-align: center;
	padding: 0 15%;
}

/* SBMH -- see http://css-discuss.incutio.com/?page=BoxModelHack 
 * Stupid hack lets IE see 100%, others see 70%. 
 */
#footer {
    \width: 100%;
    w\idth: 70%;
}

#main {
	margin-bottom: 5em;
	height: auto;
	padding: .5em;
}

http://scott.sauyet.com/CSS/Demo/FooterDemo1.html

CSS Sticky Footer

css, layout

CSS