form表單當滿足條件之後才提交表單的方法
阿新 • • 發佈：2018-12-22
使用form表單的onsubmit屬性，當屬性值為true時，則提交，當屬性值為false時，則不提交：
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>Insert title here</title> </head> <body> <script> function judge() { var username = document.getElementById("username").value; var pwd = document.getElementById("password").value; var conpwd = document.getElementById("confirmPassword").value; if(username == "") { alert("使用者名稱不能問空！"); return false; } else if(pwd!=conpwd) { alert("兩次輸入的密碼不一致！"); return false; } else return true; } </script> <h1 align="center">註冊頁 面</h1> <form action="RegisterValidate" method="post" onsubmit="return judge()"> <p align="center"> 用 戶 名：<input type="text" id="username" name="username" placeholder="輸入20個字元以內"> </p> <p align="center"> 輸入密碼：<input type="password" name="password" id="password" placeholder="輸入20個字元以內"> </p> <p align="center"> 確認密碼：<input type="password" name="confirmPassword" id="confirmPassword" placeholder="重新輸入密碼"> </p> <p align="center"> <input type="submit" value="註冊"> <input type="reset" value="重置"> </p> </form> </body> </html>