在js中显示一个时钟

实现在jsp页面中显示一个动态时钟，每隔500毫秒刷新一次，刷新时间也可以自己设置，不废话，直接上代码吧!

<srcipt>
function startTime() {
		var today = new Date();
		var y = today.getFullYear();
		var m = today.getMonth() + 1;
		var d = today.getDay();
		var h = today.getHours()
		var mn = today.getMinutes()
		var s = today.getSeconds()
		// add a zero in front of numbers<10
		m = checkTime(m)
		s = checkTime(s)
		document.getElementById('time').innerHTML = y + "-" + m + "-" + d + " "
				+ h + ":" + mn + ":" + s
		t = setTimeout('startTime()', 500)
	}

	function checkTime(i) {
		if (i < 10) {
			i = "0" + i
		}
		return i
	}
</script>

<body onload="startTime()">
<div id="time">
</body>