stopwatch.html

<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title>스톱워치</title>
		<script type="text/javascript">
			window.onload = function(){
				var startButton = document.getElementById("start");  
				var stopButton = document.getElementById("stop");
				var display = document.getElementById("display");
				var startTime, timer;
				
				startButton.onclick = start;	//start버튼 활성화
				
				function start(){
					startButton.onclick = null;
					stopButton.onclick = stop;
					startTime = new Date();
					//0.1 초마다 경과한 시간 표시
					timer = setInterval(function(){
						var now = new Date();
						display.innerHTML = ((now - startTime)/1000).toFixed(2);
					},10);
				}
				function stop(){
					clearInterval(timer);
					startButton.onclick = start;
				}
			};
			
		</script>
	</head>
	<body>
		<p id="display">0.00</p>
		<input id="start" type="button" value="start">
		<input id="stop" type="button" value="stop">
	</body>
</html>