function button_onmouseout(imgNummer) {
        if (version != "rollover_ok") return;

        var dummy1 = eval("button" + imgNummer + "aus.src");
                document ["button" + imgNummer].src = dummy1;
                return;
}
                        function button_onmouseover(imgNummer) {
                if (version != "rollover_ok") return;
                
        var dummy1 = eval("button" + imgNummer + "an.src");
                document ["button" + imgNummer].src = dummy1;
                return;
}

        var browserName = navigator.appName;
        var browserVer = parseInt(navigator.appVersion);

        if (browserName == "Microsoft Internet Explorer" && browserVer <= 3 ) {
                var version = "rollover_not_ok";
} else {
                var version = "rollover_ok";

  var button1aus = new Image(118,35);
  var button2aus = new Image(118,36);
  var button3aus = new Image(118,36);
  
  var button1an = new Image(118,35);
  var button2an = new Image(118,36);
  var button3an = new Image(118,36);

  button1aus.src = "/images/nav/1a.gif";
  button2aus.src = "/images/nav/2a.gif";
  button3aus.src = "/images/nav/3a.gif";
 
  button1an.src = "/images/nav/1b.gif";
  button2an.src = "/images/nav/2b.gif";
  button3an.src = "/images/nav/3b.gif";

}