function Clock() {
  if (!document.getElementById) return;
  theclock=document.getElementById("clock");
  now = new Date();
  hours=now.getHours();
  mins=now.getMinutes();
  secs=now.getSeconds();
  if (secs < 10) secs= "0" + secs;
  if (mins < 10) mins= "0" + mins;
  theclock.innerHTML = hours + ":" + mins + ":" + secs;
  window.setTimeout("Clock();",250);  
}