if (document.images)
{
  preload_image_object = new Image();

  image_url = new Array();
  image_url[0] = "images/arrGreenHover.png";
  image_url[1] = "images/bgNavBarBtnHover.png";
  image_url[2] = "images/btnZamowHover.png";

	  for (i = 0; i <= 3; i++) {
	   		preload_image_object.src = image_url[i];
	  }
}