function getWindowHeight() {
	var windowHeight=0;
	if (typeof(window.innerHeight)=='number') {
		windowHeight=window.innerHeight;
	} else {
		if (document.documentElement&&document.documentElement.clientHeight) {
			windowHeight=document.documentElement.clientHeight;
		} else {
			if (document.body&&document.body.clientHeight) {
				windowHeight=document.body.clientHeight;
			}
		}
	}
	return windowHeight;
}

function positionFooter() {
	if (document.getElementById) {
		var windowHeight=getWindowHeight();
		if (windowHeight>0) {
			var contentHeight=document.getElementById('content').offsetHeight;
			var footerElement=document.getElementById('footer');
			var footerHeight=footerElement.offsetHeight+20;
			if (windowHeight-(contentHeight+footerHeight)>=0) {
				footerElement.style.position='relative';
				footerElement.style.top=(windowHeight-(contentHeight+footerHeight))+'px';
			} else {
				footerElement.style.position='static';
			}
		}
	}
}