function newImage(arg) {
  if (document.images) {
    rslt = new Image();
    rslt.src = arg;
    return rslt;
  }
}

function changeImages() {
  if (document.images && (preloadFlag == true)) {
    for (var i=0; i<changeImages.arguments.length; i+=2) {
      document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
    }
  }
}

var preloadFlag = false;
function preloadImages() {
  if (document.images) {
    mich_over = newImage("Bilder/mich-over.jpg");
    videos_over = newImage("Bilder/videos-over.jpg");
    briefe_over = newImage("Bilder/briefe-over.jpg");
    kontakt_over = newImage("Bilder/kontakt-over.jpg");
    gb_over = newImage("Bilder/gb-over.jpg");
    archiv_over = newImage("Bilder/archiv-over.jpg");
    home_over = newImage("Bilder/home-over.jpg");
    haus_over = newImage("Bilder/haus-over.jpg");
    sonstiges_over = newImage("Bilder/sonstiges-over.jpg");
    preloadFlag = true;
  }
}