1 <html>
2 <head>
3 <meta charset="utf-8">
4 <title>定时警告</title>
5 </head>
6 <body>
7 <!--定时警告的问题-->
8 <h1>定时警告的问题</h1>
9 <input type="button" value="定时警告" onclick="setTimeMsg()"/>
10 <script language="javascript">
11 function setTimeMsg(){
12 setTimeout(‘alert("hello world!!!")‘,3000);//3s
13 }
14 </script>
15 <hr>
16 <!--计数器-->
17 <h1>计数器</h1>
18 <input type="button" value="开始计时" onclick="startTime()"/>
19 <input type="text" id="num"/><br>
20 <input type="button" value="结束计时" onclick="stopTime()"/>
21
22 <script language="javascript">
23 var i=0;
24 var t;
25 function startTime(){
26 document.getElementById("num").value=i;
27 i=i+1;
28 t=setTimeout("startTime()",10);//1s
29 }
30
31 function stopTime(){
32 clearTimeout(t);
33 }
34 </script>
35
36 </body>
37 </html>
1 <html>
2 <head>
3 <meta charset="utf-8">
4 <title>定时警告</title>
5 </head>
6 <body onload="startTime()">
7 <h1>秒表<div id="time"></div></h1>
8 <script language="javascript">
9 function startTime(){
10 var date=new Date();
11 var year=date.getFullYear();
12 var month=date.getMonth()+1;
13 var day=date.getDate();
14 var hour=date.getHours();
15 var minute=date.getMinutes();
16 var second=date.getSeconds();
17 //var str=year+"年"+month+"月"+day+"日"+hour+":"+minute+":"+second;
18 var str=hour+":"+minute+":"+second;
19
20 document.getElementById("time").innerHTML=str;
21 setTimeout("startTime()",1000);
22 }
23 </script>
24 </body>
25 </html>
原文：http://www.cnblogs.com/honglikeji/p/7453598.html