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) {
    home_over = newImage("/nav/home-over.jpg");
    home_new_over = newImage("/nav/home-new_over.jpg");
    new_over = newImage("/nav/new-over.jpg");
    new_features_over = newImage("/nav/new-features_over.jpg");
    features_over = newImage("/nav/features-over.jpg");
    features_gal_over = newImage("/nav/features-gal_over.jpg");
    gal_over = newImage("/nav/gal-over.jpg");
    gal_appl_over = newImage("/nav/gal-appl_over.jpg");
    appl_over = newImage("/nav/appl-over.jpg");
    appl_fin_over = newImage("/nav/appl-fin_over.jpg");
    fin_over = newImage("/nav/fin-over.jpg");
    fin_instal_over = newImage("/nav/fin-instal_over.jpg");
    instal_over = newImage("/nav/instal-over.jpg");
    instal_qual_over = newImage("/nav/instal-qual_over.jpg");
    qual_over = newImage("/nav/qual-over.jpg");
    qual_specs_over = newImage("/nav/qual-specs_over.jpg");
    specs_over = newImage("/nav/specs-over.jpg");
    specs_contact_over = newImage("/nav/specs-contact_over.jpg");
    contact_over = newImage("/nav/contact-over.jpg");
    preloadFlag = true;
  }
}