function     DivSwap    (Id)
 {
  var Obj   = document.getElementById(Id);

  if (Obj.style.display == 'block')
   {
    Obj.style.display = "none";
   }
  else
   {
    for (var i = 1; i<=1000; i++)
     {
      if (document.getElementById('div_'+i)) {document.getElementById('div_'+i).style.display='none';}
    }
    Obj.style.display = "block";
   }
 }