// Globales Flag zur Bestimmung der
  // JavaScript-Faehigkeit der Browser
  var Hilight     = false;


  // Anzahl der Images
  var before_navi_img = 2;  // wieviele img-Tags gibt's vor dem ersten Navi-Img?

  // zur Zeit aktiviertes bzw. ausgewaehltes Image
  var active      = -1;
  var selected    = -1;


  function Start()
  {
    CheckBrowser();
    LoadImages();
  }


  // Pruefen der Browserversion
  function CheckBrowser()
  {
    // Identifizierungs-Flags fuer die verschiedenen Browserversionen
    var ns          = (navigator.appName.indexOf('Netscape')!=-1);
    var ms          = (navigator.appName.indexOf('Microsoft')!=-1);
    var ver         = parseFloat(navigator.appVersion);
    var mac         = (navigator.appVersion.indexOf('Mac')!=-1);

    Hilight = false;
    if (ver >= 4.0)
    {
      if (ns == true)
        Hilight = true;
      if ( (ms == true) && (mac == false) )
        Hilight = true;
    }
  }


  function LoadImages()
  {
    if (Hilight)
    {
      imggrau = new Image();
      imggrau.src = '/html/ns_mainframe_files/navig_data/navi_punkt_grau.gif';
      imghell = new Image();
      imghell.src = '/html/ns_mainframe_files/navig_data/navi_punkt_hell_so.gif';
      imgdunkel = new Image();
      imgdunkel.src = '/html/ns_mainframe_files/navig_data/navi_punkt_dunkel_so.gif';
    }
  }



  function ActiveImage(idx)
  {
    if ( (Hilight) && (idx != active) )
    {
      if ( (active >= 0) && (active != selected) )
        document.images[before_navi_img + active - 1].src = imggrau.src;
      if ((idx >= 0) && (document.images[before_navi_img + idx - 1].src != imgdunkel.src))
        document.images[before_navi_img + idx - 1].src = imghell.src;
      active = idx;
    }
  }



  function SelectImage(idx)
  {
    if ( (Hilight) && (idx!=selected) )
    {
      if (selected >= 0)
        document.images[before_navi_img + selected - 1].src = imggrau.src;
      if ( (active != idx) && (active >= 0) )
        document.images[before_navi_img + active - 1].src = imggrau.src;
      if (idx >= 0)
        document.images[before_navi_img + idx - 1].src = imgdunkel.src;
      active   = -1;
    }
    selected = idx;
  }