function hideDiv() {
  if (document.getElementById) { // DOM3 = IE5, NS6 
    document.getElementById('hideshow').style.visibility = 'hidden';
  }
  else {
    if (document.layers) { // Netscape 4 
      document.hideshow.visibility = 'hidden';
    }
    else { // IE 4 
      document.all.hideshow.style.visibility = 'hidden';
    }
  }
}

function showDiv() {
  if (document.getElementById) { // DOM3 = IE5, NS6 
    document.getElementById('hideshow').style.visibility = 'visible';
  }
  else {
    if (document.layers) { // Netscape 4 
      document.hideshow.visibility = 'visible';
    }
    else { // IE 4 
      document.all.hideshow.style.visibility = 'visible';
    }
  }
}