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) {
    nav_mtxh_02_over = newImage("/images/nav/nav-mtxh_02-over.gif");
    nav_mtxh_05_over = newImage("/images/nav/nav-mtxh_05-over.gif");
    nav_mtxh_07_over = newImage("/images/nav/nav-mtxh_07-over.gif");
    nav_mtxh_09_over = newImage("/images/nav/nav-mtxh_09-over.gif");
    nav_mtxh_11_over = newImage("/images/nav/nav-mtxh_11-over.gif");
    nav_mtxh_13_over = newImage("/images/nav/nav-mtxh_13-over.gif");
    nav_mtxh_15_over = newImage("/images/nav/nav-mtxh_15-over.gif");
    preloadFlag = true;
  }
}