function post_construction()
{
   // let's cache all the menu images to eliminate the
   // delay when user put the mouse pointer on a menu item

   var imgCache = new Array(15);
   
   for (var i=0; i < imgCache.length; i++)
     imgCache[i] = new Image();

   imgCache[0].src = "images/about_v-e-t-s_a.gif";
   imgCache[1].src = "images/virtual_tour_a.gif";
   imgCache[2].src = "images/meet_our_staff_a.gif";
   imgCache[3].src = "images/customers_comments_a.gif";
   imgCache[4].src = "images/jobs_at_v-e-t-s_a.gif";
   imgCache[5].src = "images/maps_and_directions_a.gif";
   imgCache[6].src = "images/contact_us_a.gif";

   imgCache[7].src = "images/about_v-e-t-s_c.gif";
   imgCache[8].src = "images/virtual_tour_c.gif";
   imgCache[9].src = "images/meet_our_staff_c.gif";
   imgCache[10].src = "images/customers_comments_c.gif";
   imgCache[11].src = "images/jobs_at_v-e-t-s_c.gif";
   imgCache[12].src = "images/maps_and_directions_c.gif";
   imgCache[13].src = "images/contact_us_c.gif";

   imgCache[14].src = "images/mapbtn_dn.jpg";
}