var clockID = 0;

function UpdateClock() {
   if(clockID) {
      clearTimeout(clockID);
      clockID  = 0;
   }

   var tDate = new Date();

   document.theClock.theTime.value = "" 
                                   + tDate.getHours() + ":" 
                                   + tDate.getMinutes() + ":" 
                                   + tDate.getSeconds() ;
//                                   + (tDate.getHours() >= 12) ? " P.M." : " A.M.";
   
   clockID = setTimeout("UpdateClock()", 1000);
}
function StartClock() {
   clockID = setTimeout("UpdateClock()", 500);
}

function KillClock() {
   if(clockID) {
      clearTimeout(clockID);
      clockID  = 0;
   }
}