// JavaScript Document
var	 img = new Image();	

function change_on(ID) {
	img.src = "img/menus/" + ID + "_on.jpg";
	document.getElementById(ID).src = img.src;
} 

function change_off(ID) {
	img.src = "img/menus/" + ID + ".jpg";
	document.getElementById(ID).src = img.src;
}