function showMenu(menuNum) {
	hideAllMenus();
	document.getElementById('menu' + menuNum).style.visibility = "visible";
}

function hideAllMenus() {
	for (i = 0; i < 5; i++) {
		hideMenu(i);
	}
}

function hideMenu(menuNum) {
	document.getElementById('menu' + menuNum).style.visibility = "hidden";	
}