1 <!doctype html>
2 <html>
3 <head>
4 <meta charset="utf-8"/>
5 <title>js验证码</title>
6 <style type="text/css">
7 #login{
8 width:50px;
9 height:30px;
10 line-height:30px;
11 margin:0 auto;
12 background-color:#eee;
13 text-align:center;
14 color:red;
15 }
16 p{
17 width:75px;
18 height:30px;
19
20 margin:0 auto;
21 }
22
23 </style>
24 </head>
25 <body>
26 <p>验证码：</p>
27 <div id="login" onclick="show()"><a href="#"></a></div>
28 <script type="text/javascript">
29 function codes(n){
30 var a="azxcvbnmsdfghjklqwertyuiopZXCVBNMASDFGHJKLQWERTYUIOP0123456789";
31 var b="";
32 for (var i = 0;i<n;i++){
33 var index=Math.floor(Math.random()*62);
34 b+=a.charAt(index);
35
36 }
37 return b;
38 };
39 function show(){
40 document.getElementById("login").innerHTML=codes(4);
41
42 }
43 window.onload=show;
44
45
46 </script>
47
48 </body>
49 </html>
