if (document.images)
    {
      preload_image_object = new Image();
      // set image url
      image_url = new Array();
      image_url[0] = "images/conf_header_top_left.jpg";
      image_url[1] = "images/conf_header_top_right.jpg";
      image_url[2] = "images/conf_header_mid_left.jpg";
      image_url[3] = "images/conf_header_mid_right.jpg";
      image_url[4] = "images/conf_header_bot_left.jpg";
      image_url[5] = "images/conf_header_bot_left.jpg";
      image_url[6] = "images/home_off.jpg";
      image_url[7] = "images/home_on.jpg";
      image_url[8] = "images/about_off.jpg";
      image_url[9] = "images/about_on.jpg";
      image_url[10] = "images/prog_off.jpg";
      image_url[11] = "images/prog_on.jpg";
      image_url[12] = "images/reg_off.jpg";
      image_url[13] = "images/reg_on.jpg";
      image_url[14] = "images/accom_off.jpg";
      image_url[15] = "images/accom_off.jpg";
      image_url[16] = "images/exhib_off.jpg";
      image_url[17] = "images/exhib_on.jpg";
      image_url[18] = "images/spons_off.jpg";
      image_url[19] = "images/spons_on.jpg";
      image_url[20] = "images/advert_off.jpg";
      image_url[21] = "images/advert_on.jpg";
      image_url[22] = "images/golf_off.jpg";
      image_url[23] = "images/golf_on.jpg";
      image_url[24] = "images/faq_off.jpg";
      image_url[25] = "images/faq_on.jpg";
      image_url[26] = "images/other_off.jpg";
      image_url[27] = "images/other_on.jpg";
      image_url[28] = "images/contact_off.jpg";
      image_url[29] = "images/contact_on.jpg";

       var i = 0;
       for(i=0; i<=29; i++) 
         preload_image_object.src = image_url[i];
    }