var countMenu;
countMenu=4

function menu_on(id) {
	for(i=1;i<countMenu;i++) {
		if(i!=id) {
			document.getElementById('menu'+String(i)).style.visibility="hidden";
		}
	}
	document.getElementById('menu'+String(id)).style.visibility="visible";
}

function menu_off(id) {
	if(id<=0){
		for(i=1;i<countMenu;i++) {
			document.getElementById('menu'+String(i)).style.visibility="hidden";
		}
	}
	else{
		document.getElementById('menu'+String(id)).style.visibility="hidden";
	}
}