var makeActive = function(iframeLocation){
	elem = document.getElementById('menu');
	for(var i = 0; i < elem.getElementsByTagName('a').length; i++){
		if(elem.getElementsByTagName('a')[i].href == iframeLocation){
			elem.getElementsByTagName('a')[i].parentNode.className = 'actief';
		} else {
			elem.getElementsByTagName('a')[i].parentNode.className = '';
		}
	}
	
}