html输入的数据post到php失败
如下所示，php文件没写具体内容，应该和php无关，刚入门，求指点
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<link rel="stylesheet"href="./style.css">
<title>登入界面</title>
</head>
<body>
<div class="container">
<form action="index.php" method="POST" class="login-form">
<h1>登入</h1>
<input type="text"name="username"placeholder="用户名">
<input type="password"name="password"placeholder="密码">
<button type="submit">登入</button>
<a href="register.html">还没有账号？注册</a>
<form>
</div>
</body>
</html>
