为什么不能直接调用函数，非要在函数外再settimeout呢
<script type="text/javascript">
var num=0;
function startCount() {
document.getElementById('count').value=num;
num=num+1;
setTimeout("startCount()",1000)
}
setTimeout("startCount()",5000);
</script>
</head>
<body>
<form>
<input type="text" id="count" />
</form>
