if (document.images) {
  preload_image_object = new Image();
  // set image url
  image_url = new Array();
  var num=0;
  image_url[num++] = "/images/buton_kirmizi.gif";
  image_url[num++] = "/images/buton_kirmizi_aktif.gif";
  image_url[num++] = "/images/buton_kirmizi_hover.gif";
  image_url[num++] = "/images/buton_mavi.gif";
  image_url[num++] = "/images/buton_mavi_aktif.gif";
  image_url[num++] = "/images/buton_mavi_hover.gif";
  image_url[num++] = "/images/buton_sari.gif";
  image_url[num++] = "/images/buton_sari_aktif.gif";
  image_url[num++] = "/images/buton_sari_hover.gif";
  image_url[num++] = "/images/buton_yesil.gif";
  image_url[num++] = "/images/buton_yesil_aktif.gif";
  image_url[num++] = "/images/buton_yesil_hover.gif";

   for(var i=0; i<=num; i++)
     preload_image_object.src = image_url[i];
}