[JavaScript] 스톱워치 setInterval

setInterval 1초마다 반복

timerStart = setInterval(function() {
      time++;
      hour = addZero(parseInt(time/3600));
      min = addZero(parseInt((time%3600)/60));
      sec = addZero(parseInt(time%60));
      document.getElementById('goal_txt').innerHTML = hour+":"+min+":"+sec;
    },1000);

setInterval 정지

clearInterval(timerStart);