function hidediv(id)
{
  //safe function to hide an element with a specified id
  if (document.getElementById)
  { // DOM3 = IE5, NS6
    document.getElementById(id).style.display = 'none';
  }
  else
  {
    if (document.layers)
    { // Netscape 4
      document.id.display = 'none';
    }
    else
    { // IE 4
      document.all.id.style.display = 'none';
    }
  }
}

function unhidediv(id)
{
  //safe function to show an element with a specified id
  if (document.getElementById)
  { // DOM3 = IE5, NS6
    document.getElementById(id).style.display = 'block';
  }
  else
  {
    if (document.layers)
    { // Netscape 4
      document.id.display = 'block';
    }
    else
    { // IE 4
      document.all.id.style.display = 'block';
    }
  }
}