JavaScript实现输入验证（简单的用户注册）
1.先写用户注册页面userrAdd.jsp
<body>
<center>
<form name="f1" id="f1" action="userrAdd2.jsp" method="post" >
<table border="0">
<tr>
<td><strong>用户名</strong>:</td>
<td><input type="text" name="username" id="username" value="" maxlength="11"></td>
</tr>
<tr>
<td><strong>手机号</strong>:</td>
<td><input type="text" name="phonenumber" id="phonenumber" value="" maxlength="11"></td>
</tr>
<tr>
<td><strong>密码:</strong></td>
<td><input type="text" name="password" id="password" value="" maxlength="11"></td>
</tr>
<tr>
<td colspan="2" align="center"><input type="button" value="注册 " onclick="validate()"></td>/////////注意此处提交按钮为button，在javascript中提交
</tr>
</table>
</form>
</center>
</body>
</html>
2.然后写javascript，也在userrAdd.jsp中写在</head>前
<script type="text/javascript">
function validate()
{
var username=document.forms[0].username.value;
var phonenumber=document.forms[0].phonenumber.value;
var password=document.forms[0].password.value;
if(username.length<2){
alert("请输入合法用户名！");//////////////////////////////////////////验证用户名
}
else if(phonenumber.length<11){
alert("您的手机号应该为十一位！");////////////////////////////////////验证手机号
}
else if(password.length<6){
alert("密码至少六位！");////////////////////////////////////////////验证密码
}
else{
document.forms[0].submit();//////////////////////////////////////提交到userrAdd2.jsp
}
}
</script>
3.注册到数据库：userrAdd2.jsp
<body>
<%
request.setCharacterEncoding("utf-8");
String username=request.getParameter("username");
String phonenumber=request.getParameter("phonenumber");
String password=request.getParameter("password");
Connection con = null;
Statement stmt = null;
ResultSet rs = null;
String url = "jdbc:sqlserver://127.0.0.1:1433;databaseName=student;user=sa;password=1";//sa身份连接
Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
con = DriverManager.getConnection(url);
stmt = con.createStatement();
String SQL = "insert into userr values('"+username+"','"+phonenumber+"','"+password+"')";
stmt.execute(SQL);
%>
注册成功
</body>
4.结果截图
