n = 8; // number of hidden layers

function show(a, o)
{
  clearTimeShow();
  //var curDisplay = document.getElementById('t'+a).style.display;
  for(i=1;i<=n;i++)
  {
    if(document.getElementById('t'+i) != undefined)
    {
      document.getElementById('t'+i).style.display = 'none';
    }
  }
  if(o == 1)
  {
    if(document.getElementById('t'+a) != undefined)
    {
      document.getElementById('t'+a).style.display = 'inline';
    }
  } 
}

var currentTimer;

function timeShow()
{
  if(currentTimer != undefined)
  {
    clearTimeout(currentTimer);
    currentTimer = undefined;
  }
  currentTimer = setTimeout('show(0,0)',300);
}

function clearTimeShow()
{
  if(currentTimer != undefined)
  {
    clearTimeout(currentTimer);
    currentTimer = undefined;
  }
}