glideTimer = 0;
   glideInterval = 2718;
   glideIndex = 0;
   function startGlider(id) {
     glideTimer = window.setTimeout("animateGliderById('" + id + "')", glideInterval);
   }
   function animateGliderById (id) {
     target = document.getElementById(id);
     if (target != undefined) {
       glideIndex = glideIndex + 1;
       if (glideIndex == 4) glideIndex = 0;
       target.style.backgroundImage = "url(glider" + glideIndex + "-27x27.png)";
       glideTimer = window.setTimeout("animateGliderById('" + id + "')", glideInterval);
      }
   }