setInterval、控制停止和继续

<script src="../js/jquery-1.4.2.js" type="text/javascript"></script>

<div id="one">
	0
	</div>
	<script type="text/javascript">
	var one = document.getElementById("one");
	var i = 0;
	var dt = setInterval(function(){
			one.innerText=i;
			i++;
			}, 100);
	function stop(){
		clearInterval(dt);
	}
	function star(){
		dt = setInterval(function(){
			one.innerText=i;
			i++;
			}, 100);
	}
	</script>
	<input type="button" onclick="stop()" value="停止"/>
	<input type="button" onclick="star()" value="开始"/>