function changeImg (id,on)
{
	obj = document.getElementById(id);
	if (on)
		obj.src = obj.src.replace ("-off","-on");
	else
		obj.src = obj.src.replace ("-on","-off");
}

function showMenu(module)
{
	var menu = document.getElementById(module);
	if (menu)
		menu.className = "menu_on";
}