if (document.images)
    {
      preload_image_object = new Image();
      // set image url
      image_url = new Array();
      image_url[0] = "../images/btnHomeOn.jpg";
      image_url[1] = "../images/btnInventoryOn.jpg";
      image_url[2] = "../images/btnCopartOn.jpg";
      image_url[3] = "../images/btnAboutOn.jpg";
	  image_url[4] = "../images/btnShippingOn.jpg";
	  image_url[5] = "../images/btnFaqsOn.jpg";
	  image_url[6] = "../images/btnExtraOn.jpg";
	  image_url[7] = "../images/btnCarsOn.jpg";
	  image_url[8] = "../images/btnMiniVansOn.jpg";
	  image_url[9] = "../images/btnSuvsOn.jpg";
	  image_url[10] = "../images/btnPickupsOn.jpg";
	  image_url[11] = "../images/btnAuctionOn.jpg";

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