function ukaz_podmenu(menu_item)
{
  document.getElementById("podmenu" + menu_item).style.visibility = "visible";
  document.getElementById("menu"+menu_item).className = "selected";
}

function smaz_podmenu(menu_item)
{
  document.getElementById("menu"+menu_item).className="";
  document.getElementById("podmenu" + menu_item).style.visibility = "hidden";
}