<form action="" method="post" novalidate><!--提交时不验证--> <h2>提交时不验证</h2> <h3>登录</h3> <div> <label for="user_name">用户名</label> <input id="user_name" name="user_name" autofocus="" required=""><!-- 用户名表单 --> </div> <div> <label for="password">密码</label> <input id="password" name="password" type="password" autocomplete="off" value="" required=""><!--密码表单--> </div> <div> <button type='submit'>登录</button> </div> </form> <form action="" method="post"><!--提交时验证--> <h2>提交时验证</h2> <h3>登录</h3> <div> <label for="user_name">用户名</label> <input id="user_name" name="user_name" autofocus="" required=""><!-- 用户名表单 --> </div> <div> <label for="password">密码</label> <input id="password" name="password" type="password" autocomplete="off" value="" required=""><!--密码表单--> </div> <div> <button type='submit'>登录</button> </div> </form>