function menu_link(object, hover) {
  object.className = hover ? 'menu_on' : 'menu_off'
}

function ro(who) {
  var tmp = "";
  if (who.src.indexOf("_off") != -1)
	tmp = who.src.replace("_off", "_on")
  else
	tmp = who.src.replace("_on", "_off")
  who.src = tmp
}