function updateClock ()
{
  var currentTime = new Date ( );
  var currentHours = currentTime.getHours ( );
  var currentMinutes = currentTime.getMinutes ( );
  var currentSeconds = currentTime.getSeconds ( );
  currentMinutes = ( currentMinutes < 10 ? "0" : "" ) + currentMinutes;
  currentSeconds = ( currentSeconds < 10 ? "0" : "" ) + currentSeconds;
  var currentTimeString = currentHours + ":" + currentMinutes + ":" + currentSeconds + " ";
  document.getElementById("clock").firstChild.nodeValue = currentTimeString;
}