经我修正后可以正常运作了
<!DOCTYPE HTML><html>
<head>
<title> </title>
<script type="text/javascript">
var t=null
function starTime()
{
t = setInterval(function(){
var day=new Date()
var h=day.getHours()
var m=day.getMinutes()
var s=day.getSeconds()
h=checkTime(h)
m=checkTime(m)
s=checkTime(s)
var time=h+":"+m+":"+s
var obj= document.getElementById('time')
obj.innerHTML=time
},1000)
//t=setTimeout('startTime()',1*1*1000)
}
function checkTime(i)
{
if(i<10)
{i="0"+i}
return i
}
function stopTime(){
clearInterval(t)
}
</script>
</head>
<body onload="starTime()" >
<div id="time" style="text-align:center height:50px lin-height:50pxcolor:red"></div>
<input type="button" value="开始" id="start" onclick="starTime()">
<input type="button" value="暂停" id="stop" onclick="stopTime()">
</body>
</html>
<html><head><script type="text/javascript">function startTime(){var today=new Date()var h=today.getHours()var m=today.getMinutes()var s=today.getSeconds()// add a zero in front of numbers<10m=checkTime(m)s=checkTime(s)document.getElementById('txt').innerHTML=h+":"+m+":"+st=setTimeout('startTime()',500)} function checkTime(i){if (i<10) {i="0" + i} return i}</script></head><body onload="startTime()"><div id="txt"></div></body></html>setTimeout定时document.write以后，重新打开输出流，会清空页面内容，包括你以前的代码，简单改了一下：<script>
function tick() {
var hours, minutes, seconds, xfile
var intHours, intMinutes, intSeconds
var today
today = new Date()
intHours = today.getHours()
intMinutes = today.getMinutes()
intSeconds = today.getSeconds()
if (intHours == 0) {
hours = "12:"
xfile = "午夜"
} else if (intHours <12) {
hours = intHours+":"
xfile = "上午"
} else if (intHours == 12) {
hours = "12:"
xfile = "正午"
} else {
intHours = intHours - 12
hours = intHours + ":"
xfile = "下午"
}
if (intMinutes <10) {
minutes = "0"+intMinutes+":"
} else {
minutes = intMinutes+":"
}
if (intSeconds <10) {
seconds = "0"+intSeconds+" "
} else {
seconds = intSeconds+" "
}
timeString = xfile+hours+minutes+seconds
document.getElementById("t").innerHTML=timeString
window.setTimeout("tick()", 1000)
}
window.onload=tick
</script>
<div id="t"></div>
================================
Clock.innerHTML = timeString
定时重写clock的内容，达到时钟效果
