function showsub(my_id) {
	// shows a submenu
	document.getElementById(my_id).style.visibility="visible"; 
	document.getElementById(my_id).parentNode.style.borderColor="#000060";
}

function unshowsub(my_id) {
	// unshows a submenu
	document.getElementById(my_id).style.visibility="hidden";
	document.getElementById(my_id).parentNode.style.borderColor="#D0D8F8";
}