if(navigator.appVersion.charAt(0) >= 3) {
   var img = new Array();
   img[1] = new Image();
   img[1].src = "/images/change/botton1_on.jpg";
   img[2] = new Image();
   img[2].src = "/images/change/botton2_on.jpg";
   img[3] = new Image();
   img[3].src = "/images/change/botton3_on.jpg";
   img[4] = new Image();
   img[4].src = "/images/change/botton1_off.jpg";
   img[5] = new Image();
   img[5].src = "/images/change/botton2_off.jpg";
   img[6] = new Image();
   img[6].src = "/images/change/botton3_off.jpg";
  }

function change_image(nam,num) {
    if(navigator.appVersion.charAt(0) >= 3) {
    document.images[nam].src = img[num].src;
    }
}