慕课网编译器停不下来
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>计时器</title>
<script type="text/javascript">
function clock(){
var time=new Date();
document.getElementById("clock").value = time;
}
function i()
{
j=setInterval(clock,500);
document.getElementById("clo").value =j;
}
</script>
</head>
<body>
<form>
<input type="text" id="clock" size="50" />
<input type="text" id="clo" size="10" />
<input type="button" value="Stop" onclick="clearInterval(j)" />
<input type="button" value="Start" onclick="i()" />
</form>
</body>
</html>
