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) {
    m01_dates_over = newImage("gfx/design/m01b_dates-over.jpg");
    m02_projects_over = newImage("gfx/design/m02b_projects-over.jpg");
    m03_lyrics_over = newImage("gfx/design/m03b_lyrics-over.jpg");
    m04_pictures_over = newImage("gfx/design/m04b_pictures-over.jpg");
    m05_imprint_over = newImage("gfx/design/m05b_imprint-over.jpg");
    preloadFlag = true;
  }
}