// Menu javascript

function open_submenu ( main_item, sub_item ) {
  if (document.getElementById(main_item + "-submenu"))
    document.getElementById(main_item + "-submenu").style.display = "block";
  if (document.getElementById(sub_item + "-submenu-item"))
    document.getElementById(sub_item + "-submenu-item").className += " submenu-selected";
  if (document.getElementById(main_item + "-menu-item"))
    document.getElementById(main_item + "-menu-item").className += " menu-selected";
    
}