var lastImg = "";

function switchImg(name)
{
  if (document.layers)
    layer = eval('document.layers.ebene');
  else
    layer = eval('document.all.ebene');

  if (layer != null)
  {
    layer.document.images[actImage].src = "images/menu/" + actImage + "_i.gif";
    layer.document.images[name].src = "images/menu/" + name + "_a.gif";
    lastImg = name;
  }
}

function switchBack()
{
  if (document.layers)
    layer = eval('document.layers.ebene');
  else
    layer = eval('document.all.ebene');

  if (layer != null)
  {
    if (lastImg != "")
      layer.document.images[lastImg].src = "images/menu/" + lastImg + "_i.gif";
    layer.document.images[actImage].src = "images/menu/" + actImage + "_a.gif";
  }
}