<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>post</title>
</head>
<body>
<form action="" method="post">
<label for="email">邮箱:</label>
<input type="email" id="email" name="email" value="">
<label for="password">密码:</label>
<input type="password" id="password" name="password" value="">
<button>登录</button>
</form>
</body>
</html>
<?php
echo ($_POST['email']);
echo '<hr>';
echo ($_POST['password']);
echo '<hr>';
$str = 'SHANGHAI';
echo strtolower($str);
?>