if (document.images)
    {
      preload_image_object = new Image();
      // set image url
      image_url = new Array();
      image_url[0] = "http://www.columbiarovers.com/wp-content/themes/colrovers_v1/images/banners/header_bg2.jpg";
      image_url[1] = "http://www.columbiarovers.com/wp-content/themes/colrovers_v1/images/banners/header_bg3.jpg";
      image_url[2] = "http://www.columbiarovers.com/wp-content/themes/colrovers_v1/images/banners/header_bg4.jpg";
      image_url[3] = "http://www.columbiarovers.com/wp-content/themes/colrovers_v1/images/banners/header_bg5.jpg";
	  image_url[4] = "http://www.columbiarovers.com/wp-content/themes/colrovers_v1/images/banners/header_bg6.jpg";
	  image_url[5] = "http://www.columbiarovers.com/wp-content/themes/colrovers_v1/images/banners/header_bg7.jpg";
	  image_url[6] = "http://www.columbiarovers.com/wp-content/themes/colrovers_v1/images/banners/header_bg1.jpg";

       var i = 0;
       for(i=0; i<=6; i++) 
         preload_image_object.src = image_url[i];
    }