注册页面的js验证

简单的用户注册页面：(html)
包含用户名格式验证、邮箱格式验证、确认密码一致性验证和必填项验证。(纯javascript)
 1 <center>
 2     <h1>用户注册</h1>
 3     <hr>
 4     <SCRIPT type="text/javascript">
 5     function isEmail(strEmail) {
 6         if (strEmail.search(/^w+((-w+)|(.w+))*@[A-Za-z0-9]+((.|-)[A-Za-z0-9]+)*.[A-Za-z0-9]+$/) != -1)
 7             return true;
 8         else {
 9             alert("邮箱格式不对");
10             return false;
11         }
12     }
13 
14     function isUsername(un) {
15         if (un.search(/^[a-zA-Z0-9_]{1,20}$/) != -1) return true;
16         else {
17             alert("用户名只能由1～20位长度的数字、英文字母或者下划线组成");
18             return false;
19         }
20     }
21 
22     function checkSubmit() {
23         if (document.getElementById("username").value == "") {
24             alert("请填写用户名!");
25             return false;
26         }
27         if (document.getElementById("email").value == "") {
28             alert("请填写邮箱!");
29             return false;
30         }
31         var pwd1 = document.getElementById("password1");
32         var pwd2 = document.getElementById("password2");
33         if (pwd1.value == "") {
34             alert("请填写密码!");
35             return false;
36         }
37         if (pwd2.value == "") {
38             alert("请再次填写密码!");
39             return false;
40         }
41         if (pwd1.value != pwd2.value) {
42             alert("密码不一致");
43             return false;
44         }
45     }
46     </SCRIPT>
47     <form name="Register" method="post">
48         <table>
49             <tr>
50                 <td align="center">用户名*:</td>
51                 <td>
52                     <input type="text" name="username" id="username" onblur="isUsername(this.value)">
53                 </td>
54             </tr>
55             <tr>
56                 <td align="center">邮箱*:</td>
57                 <td>
58                     <input type="text" name="email" id="email" onblur="isEmail(this.value)">
59                 </td>
60             </tr>
61             <tr>
62                 <td align="center">密码*:</td>
63                 <td>
64                     <input type="password" id="password1" name="password1">
65                 </td>
66             </tr>
67             <tr>
68                 <td align="center">密码确认*:</td>
69                 <td>
70                     <input type="password" name="password2" id="password2">
71                 </td>
72             </tr>
73             <tr>
74                 <td align="center"><a href="/horizon/auth/login">返回 </a></td>
75                 <td>
76                     <input type="submit" value="注册!" onclick="return checkSubmit()">
77                 </td>
78             </tr>
79         </table>
80     </form>
81 </center>