menu0 = new Image ();
menu0.src = 'img/menu0a.gif';
menu1 = new Image ();
menu1.src = 'img/menu1a.gif';
menu2 = new Image ();
menu2.src = 'img/menu2a.gif';
menu3 = new Image ();
menu3.src = 'img/menu3a.gif';

function on (img) {
	img.src = 'img/' + img.name + 'a.gif';
}
function off (img) {
	img.src = 'img/' + img.name + '.gif';
}