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 setFooter() {
	if (document.getElementById) {
		var windowHeight=getWindowHeight();
		if (windowHeight>0) {
			var contentHeight=document.getElementById('wrapper').offsetHeight;
			var footerElement=document.getElementById('footer');
			var footerHeight=footerElement.offsetHeight;
			if (windowHeight-(contentHeight+footerHeight)>=0) {
				footerElement.style.position='relative';
				footerElement.style.top=(windowHeight-(contentHeight+footerHeight))+'px';
				}
			else {
				footerElement.style.position='static';
				}
			}
	}
}
function init() {
  setFooter();
}
window.onresize = function() {
  setFooter();
};
window.onload = init;