setInterval("settime()", 10000);
 
function settime () {
  var curtime = new Date();
  var curhour = curtime.getHours();
  var curmin = curtime.getMinutes();
  var cursec = curtime.getSeconds();
  var time = "";
 
  if(curhour == 0) curhour = 12;
  time = (curhour > 12 ? curhour - 12 : curhour) + ":" +
         (curmin < 10 ? "0" : "") + curmin +
         (curhour > 12 ? " PM" : " AM");
 
  document.getElementById("clock").innerHTML = time;
  
}