if (parseInt(navigator.appVersion.substring(0,1))>=3) { // 3.0 or greater.
img1_on = new Image();
img1_off = new Image();

img1_on.src = '/iconz/menu01_over.gif';
img1_off.src = '/iconz/menu01.gif';

img2_on = new Image();
img2_off = new Image();

img2_on.src = '/iconz/menu02_over.gif';
img2_off.src = '/iconz/menu02.gif';

img3_on = new Image();
img3_off = new Image();

img3_on.src = '/iconz/menu03_over.gif';
img3_off.src = '/iconz/menu03.gif';

img4_on = new Image();
img4_off = new Image();

img4_on.src = '/iconz/menu04_over.gif';
img4_off.src = '/iconz/menu04.gif';

}

function on(image) {
  if (parseInt(navigator.appVersion.substring(0,1))>=3) { // 3.0 or greater.
      imgrc = eval(image + '_on.src');
      document[image].src = imgrc;
  }
}

function off(image) {
  if (parseInt(navigator.appVersion.substring(0,1))>=3) { // 3.0 or greater.
      imgrc = eval(image + "_off.src");
      document[image].src = imgrc;
 }
}