function layoutGuard() {
    var documentheight = document.documentElement.clientHeight;
	var contentheight = document.getElementById('maincontent').offsetHeight;
	contentheight = (contentheight*1+163);
	if (documentheight>contentheight) {
		//alert('footer laag zetten');
		document.getElementById('footer').style.bottom = '0px';
	} else {
		document.getElementById('footer').style.bottom = '';
	}
	//alert(contentheight);
	//alert(h);
}