js计时器

<script type="text/javascript">
//计时因子
var c = 0;
var t;
function timedCount() {
var temptextmin = document.getElementById('txt');
//根据计时因子获取小时数和分钟数
hour = parseInt(c / 3600);// 小时数
min = parseInt(c / 60);// 分钟数
if (min >= 60) {
min = min % 60;
}
lastsecs = c % 60;//秒数

temptextmin.value = hour + "时" + min + "分" + lastsecs + "秒";
//计时因子加1
c = c + 1;
//启动计时器
t = setTimeout("timedCount()", 1000);
document.getElementById('start').style.display = "none";
document.getElementById('end').style.display = "";
}

function stopCount() {
//清除计时器
clearTimeout(t);
document.getElementById('start').style.display = "";
document.getElementById('end').style.display = "none";
}
function clearAll() {
//计时因子置0
c = 0;
//重新初始化txt值
document.getElementById('txt').value = "0时" + "0分" + "0秒";
clearTimeout(t);
document.getElementById('start').style.display = "";
document.getElementById('end').style.display = "none";
}
</script>

<pre name="code" class="html"><input type="text" id="txt" value="0时0分0秒">
<input type="button" value="开始计时！" id="start" onclick="timedCount()">
<input type="button" value="停止计时！" style="display: none" id="end" onclick="stopCount()">
<input type="button" value="清除" onclick="clearAll()">
<p>请点击上面的“开始计时”按钮来启动计时器。输入框会一直进行计时，从 0 开始。点击“停止计时”按钮可以终止计时。</p>