<!doctype html> <html lang="en"> <head> <meta charset="UTF-8"> <title>JavaScript内置对象</title> <style> input{ width:300px; height:40px; line-height:40px; } </style> </head> <body> <h1>表单验证</h1> <hr> <form name="reg_form" method="post" action="1.php" onsubmit="return checkForm()"> <table> <tr> <td>用户名</td> <td><input type="text" name="username"></td> </tr> <tr> <td>邮箱</td> <td><input type="text" name="email"></td> </tr> <tr> <td>密码</td> <td><input type="password" name="pass"></td> </tr> <tr> <td>确认密码</td> <td><input type="password" name="repass"></td> </tr> <tr> <td></td> <td><input type="submit" value="注 册"></td> </tr> </table> </form> <script> function checkForm(){ //验证用户名 6-12位的数字、字母、下划线 var value = document.reg_form.username.value; if (value.search(/^w{6,12}$/) == -1) { alert("用户名必须是6-12位的数字、字母、下划线") return false; } //验证邮箱 test@qq.com var value = document.reg_form.email.value; if (value.match(/^[w-]+@[w-]+(.[w]+){1,3}$/) == null) { alert("邮箱格式不正确"); return false; } //判断密码 长度6-18位 var value = document.reg_form.pass.value; if (value.length < 6 || value.length > 18) { alert("密码长度必须6-18位"); return false; } var repass = value; //确认密码 var value = document.reg_form.repass.value; if (value != repass) { alert("两次密码不一致"); return false; } return true; } </script> </body> </html>