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) {
    dwwcc2008_masthead_16_over = newImage("/images/nav/dwwcc2008-masthead_16-over.gif");
    dwwcc2008_masthead_17_over = newImage("/images/nav/dwwcc2008-masthead_17-over.gif");
    dwwcc2008_masthead_18_over = newImage("/images/nav/dwwcc2008-masthead_18-over.gif");
    dwwcc2008_masthead_19_over = newImage("/images/nav/dwwcc2008-masthead_19-over.gif");
    dwwcc2008_masthead_20_over = newImage("/images/nav/dwwcc2008-masthead_20-over.gif");
    dwwcc2008_masthead_24_over = newImage("/images/nav/dwwcc2008-masthead_24-over.gif");
    dwwcc2008_masthead_25_over = newImage("/images/nav/dwwcc2008-masthead_25-over.gif");
    dwwcc2008_masthead_26_over = newImage("/images/nav/dwwcc2008-masthead_26-over.gif");
    dwwcc2008_masthead_27_over = newImage("/images/nav/dwwcc2008-masthead_27-over.gif");
    dwwcc2008_masthead_28_over = newImage("/images/nav/dwwcc2008-masthead_28-over.gif");
    dwwcc2008_masthead_29_over = newImage("/images/nav/dwwcc2008-masthead_29-over.gif");
    preloadFlag = true;
  }
}