var count = 0;
var msecsFirst = 0;
var msecsPrevious = 0;

function ResetCount()
  {
  count = 0;
  document.forms[0].T_AVG.value = "";
  document.forms[0].T_TAP.value = "";
  document.forms[0].T_RESET.blur();
  }

function TapForBPM(e)
  {
  document.forms[0].T_WAIT.blur();
  timeSeconds = new Date;
  msecs = timeSeconds.getTime();
  if ((msecs - msecsPrevious) > 1000 * document.forms[0].T_WAIT.value)
    {
    count = 0;
    }

  if (count == 0)
    {
    document.forms[0].T_AVG.value = "Eka biitti";
    document.forms[0].T_TAP.value = "Eka biitti";
    msecsFirst = msecs;
    count = 1;
    }
  else
    {
    bpmAvg = 60000 * count / (msecs - msecsFirst);
    document.forms[0].T_AVG.value = (Math.round(bpmAvg * 100)) / 100;
    count++;
    document.forms[0].T_TAP.value = count;
    }
  msecsPrevious = msecs;
  return true;
  }
document.onkeypress = TapForBPM;