表单验证

1.    function mysubmit(){  
2.                if(check()){  
3.                    alert("mainok");  
4.                    document.getElementById("form1").submit();  
5.                }  
6.            }  
7.            function check(){  
8.                var username=document.getElementById("username").value;  
9.                var password=document.getElementById("password").value;  
10.                var repassword=document.getElementById("repassword").value;  
11.                var email=document.getElementById("email").value;  
12.                var mobile=document.getElementById("mobile").value;  
13.                var birthday=document.getElementById("birthday").value;  
14.                if(username==null||username==""){  
15.                    alert("用户名不能为空");  
16.                    document.getElementById("username").focus();  
17.                    return false;  
18.                }  
19.                if(username.length<5){  
20.                    alert("用户名长度为5-20个字符");  
21.                    document.getElementById("username").focus();  
22.                    return false;  
23.                }  
24.                if(password==null||password==""){  
25.                    alert("密码不能为空");  
26.                    document.getElementById("password").focus();  
27.                    return false;  
28.                }  
29.                if(password.length<6||password.length>20){  
30.                    alert("密码长度为6-20个字符");  
31.                    document.getElementById("password").focus();  
32.                    return false;  
33.                }  
34.                if(password!=repassword){  
35.                    alert("密码不一致");  
36.                    document.getElementById("password").focus();  
37.                    return false;  
38.                }  
39.                if(email==null||email==""){  
40.                    alert("邮箱不能为空");  
41.                    document.getElementById("email").focus();  
42.                    return false;  
43.                }  
44.                if(email.indexOf("@")==-1){  
45.                    alert("邮箱格式错误");  
46.                    document.getElementById("email").focus();  
47.                    return false;  
48.                }  
49.                var str=/^1[3|4|5|8][0-9]\d{8}$/;  
50.                if(mobile!=null&&mobile!=""){  
51.                    if(!str.test(mobile)){  
52.                        alert("手机格式错误");  
53.                        document.getElementById("mobile").focus();  
54.                        return false;  
55.                    }  
56.                }  
57.                  
58.                return true;  
59.            }  
60.            function checkname(){  
61.                var username=document.getElementById("username").value;  
62.                $.ajax({  
63.                    type:"post",  
64.                    url:"checkname",  
65.                    data:{  
66.                        username:username  
67.                    },  
68.                    success:function(data){  
69.                        //alert(data);  
70.                        if(data=="true"){  
71.                            document.getElementById("username").focus();  
72.                            alert("用户存在");  
73.                            return false;  
74.                        }  
75.                    }  
76.                })  
77.            }