var menuactief = 0;
function toonMenu(pMenu) {
	for(i=1;i<=5;i++) {
		if (i != menuactief) {
			document.getElementById("menu"+i).style.visibility='hidden';	
			document.getElementById("blok"+i).style.visibility='visible';	
		}
	}
	if (pMenu > 0) {
		document.getElementById("menu"+pMenu).style.visibility='visible';	
		document.getElementById("blok"+pMenu).style.visibility='hidden';	
	}
}