<!DOCTYPE html>
<html>
<head>
<title>作业</title>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<style type="text/css">
input {
width: 300px;
text-align: center;
}
</style>
<script type="text/javascript">
var hour = 0;
var minute = 0;
var second = 0;
var interval;
var flag = true;
window.onload = function() {
//当按钮点击时
document.getElementById("btn").onclick = function() {
this.disabled = "disabled";
//time();
interval = window.setInterval("time()", 1000);
};
//对暂停继续按钮进行注册事件
document.getElementById("btn1").onclick = function() {
if (flag) {
window.clearInterval(interval);
} else {
interval = window.setInterval("time()", 1000);
}
flag=!flag;
};
}
var time = function() {
second++;
if (second >= 60) {
minute++;
second = 0;
}
if (minute >= 60) {
minute = 0;
hour++;
}
hour = parseInt(hour) > 9 ? hour : "0" + parseInt(hour);
minute = parseInt(minute) > 9 ? minute : "0" + parseInt(minute);
second = parseInt(second) > 9 ? second : "0" + parseInt(second);
document.getElementById("txt").value = hour + ":" + minute + ":"
+ second;
//让上面的代码，每间隔一秒钟执行一次.
//setTimeout("time()", 1000);
}
</script>
</head>
<body>
<input type="text" id="txt" readonly="readonly">
<br>
<input type="button" value="开始" id="btn">
<br>
<input type="button" value="暂停/继续" id="btn1">
</body>
</html>
