var x;
function akt(nummer,status) {
  if (document.images || navigator.userAgent.indexOf("opera") != "-1")
    {
    if (x != nummer) document["nav_"+nummer].src="images/nav_"+ nummer + status+".gif";
    }
}

function setPage(nummer) {
if (document.images || navigator.userAgent.indexOf("opera") != "-1")
  {
  if (x != nummer)
    {
    document["nav_"+nummer].src="images/nav_" + nummer + "d.gif";
    if (x) document["nav_"+x].src="images/nav_" + x + "u.gif";
    }
    x = nummer;
  }
}

function ResetPage() {
if (document.images || navigator.userAgent.indexOf("opera") != "-1")
  {
  if (x) document["nav_"+x].src="images/nav_" + x + "u.gif";
  x = "";
  }
}