function updateClock() {

  var currentTime = new Date();

  var currentHours = currentTime.getHours();
  var currentMinutes = currentTime.getMinutes();
  var currentSeconds = currentTime.getSeconds();

  currentHours = (currentHours < 10 ? "0" : "") + currentHours;
  currentMinutes = (currentMinutes < 10 ? "0" : "") + currentMinutes;
  currentSeconds = (currentSeconds < 10 ? "0" : "") + currentSeconds;

  var currentTimeString = currentHours + ":" + currentMinutes + ":" + currentSeconds;

  document.getElementById("clock").firstChild.nodeValue = " - " + currentTimeString;
  }