function loadSubMenu(id) {
  if ($('submenu_' + id)) {
    $('submenu').innerHTML = $('submenu_' + id).innerHTML;
    $('submenu_arrow').style.visibility = 'visible';
  }
  else {
    $('submenu').innerHTML = ' ';
    $('submenu_arrow').style.visibility = 'hidden';
  }
}

function init() {
}