* {
	margin: 0;
}
html, body {
	height: 100%;
}
.wrapper {
	min-height: 100%;
	height: auto !important;
	height: 100%;
	margin: 0 auto -4em; /* the bottom margin is the negative value of the footer's height */
}
.footer, .push {
	height: 4em; /* .push must be the same height as .footer */
}

http://ryanfait.com/sticky-footer/

STICKER - A valid, easy to use CSS sticky footer by Ryan Fait

This is the basic CSS you need along with the one extra empty
div and the wrapper required to achieve the effect. I suggest
that you leave the * { margin: 0; } code in while testing and
building your site because margins do have a tendency to mess
things up a bit. Have fun!

Copyright (c) 2006-2007 Ryan Fait

/*

TROUBLESHOOTING

I've received a few comments about vertical margins causing a
few problems with the layout. If you want space between
paragraphs or headers, use padding instead of margin. It's as
simple as that.

*/

STICKER - A valid, easy to use CSS sticky footer

css, layout

CSS