defaultStatus = "";
var rootDirectory = "img/";

if (document.images) {

  nahoruon = new Image(19, 15);
  nahoruon.src = rootDirectory + "TH_nahoru.gif";
  nahoruoff = new Image(19, 15);
  nahoruoff.src = rootDirectory + "TL_nahoru.gif";

  uvodon = new Image(53, 30);
  uvodon.src = rootDirectory + "NH_uvod.gif";
  uvodoff = new Image(53, 30);
  uvodoff.src = rootDirectory + "NL_uvod.gif";

  historieon = new Image(142, 30);
  historieon.src = rootDirectory + "NH_historie.gif";
  historieoff = new Image(142, 30);
  historieoff.src = rootDirectory + "NL_historie.gif";

  kampanon = new Image(146, 30);
  kampanon.src = rootDirectory + "NH_kampan.gif";
  kampanoff = new Image(146, 30);
  kampanoff.src = rootDirectory + "NL_kampan.gif";

  karieraon = new Image(137, 30);
  karieraon.src = rootDirectory + "NH_kariera.gif";
  karieraoff = new Image(137, 30);
  karieraoff.src = rootDirectory + "NL_kariera.gif";

  registraceon = new Image(83, 30);
  registraceon.src = rootDirectory + "NH_registrace.gif";
  registraceoff = new Image(83, 30);
  registraceoff.src = rootDirectory + "NL_registrace.gif";

  kontakton = new Image(63, 30);
  kontakton.src = rootDirectory + "NH_kontakt.gif";
  kontaktoff = new Image(63, 30);
  kontaktoff.src = rootDirectory + "NL_kontakt.gif";

  katalogon = new Image(113, 30);
  katalogon.src = rootDirectory + "NH_katalog.gif";
  katalogoff = new Image(113, 30);
  katalogoff.src = rootDirectory + "NL_katalog.gif";
 }

function On(imgName) {
  if (document.images)
    document.images[imgName].src = eval(imgName + "on.src");
}

function Off(imgName) {
  if (document.images)
    document.images[imgName].src = eval(imgName + "off.src");
}