function highlight(ref) {
  var div = ref.parentNode.style;
  div.backgroundImage = "url('./static/img2/menubg.png')";
  div.backgroundRepeat = "no-repeat";
}

function unhighlight(ref) {
  var div = ref.parentNode.style;
  if(ref.parentNode.className != "x_menu_selected") {
    div.backgroundImage = "none";
  }
}