var intActiveMenu = 0;

function showmenu(intid) {
	document.getElementById('hoofdmenu'+intid).style.visibility = 'visible';
	intActiveMenu = intid;
	hideAllInactiveMenus();
	return;
}

function hidemenu(intid) {
	intActiveMenu = 0;
	return;
}

function hideAllInactiveMenus() {
	for(i=1;i<(4+1);i++) {
		if (intActiveMenu != i) document.getElementById('hoofdmenu'+i).style.visibility = 'hidden';
	}
	return;
}

function timedHidingOfMenus() {
	hideAllInactiveMenus();
	setTimeout("timedHidingOfMenus()",500);
	return;
}