function show_menu(menu, left){
	menu = document.getElementById(menu);
	menu.style.left = left;
	menu.style.display = 'block';
}
function hide_menu(menu){
	document.getElementById(menu).style.display = 'none';
}
function selected(item){
	item.style.backgroundColor = 'cyan';
}
function unselected(item){
	item.style.backgroundColor = 'white';
}
function go(href){
	window.location.href = href;
}