我这段js计时器的开始和停止按钮的代码哪有错误?
<!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;
}
var i=setInterval(function(){
clock()
},100)
function clock2(){
clearInterval(i)
}
function clock3(){
var i=setInterval(function(){
clock()},100)
}
</script>
</head>
<body>
<form>
<input type="text" id="clock" size="50" />
<input type="button" value="Stop" onclick="clock2()" />
<input type="button" value="Continue" onclick="clock3()">
</form>
</body>
</html>
按了continue之后再按stop就无效了,该怎么改