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(document.body && (document.body.scrollLeft || document.body.scrollTop))
			var scrollHeight = document.body.scrollTop;
		else
			var scrollHeight = document.documentElement.scrollTop;
		//var debug = document.getElementById('debug');
		
		if (windowHeight > 0) {
			var contentHeight = document.getElementById('c').offsetHeight;
			var footerElement = document.getElementById('footer-menu');
			var footerHeight  = footerElement.offsetHeight;
			
			footerElement.style.top = (windowHeight - footerHeight + scrollHeight) + 'px';
		}
	}

}

window.onload = function() {
	setFooter();
}

window.onresize = function() {
	setFooter();
}

window.onscroll = function() {
	setFooter();
}