function showsub(id) {
    div = document.getElementById("t" + id);
    div.style.display = "block";
  }

  function hidesub(id) {
    div = document.getElementById("t" + id);
    div.style.display = "none";
  }
  
  function show(element){
           element.className += "hover";
   }
 function hide(element){
           element.className = element.className = "";
     }