<?php
     if(empty($_GET)){
        ?>
<form action="" method="GET">
    <input name = "login" placeholder="Login"></br>
    <input name = "password" placeholder="Password"></br>
    <input type = submit>
</form>
<?php
    } else {

    $host = "localhost";
    $user= "root";
    $pass = "root";
    $name = "test";
    $link = mysqli_connect($host, $user, $pass, $name);

    $login = $_GET['login'];
    $password = $_GET['password'];
    $query = mysqli_query($link,"SELECT * FROM users WHERE login = '$login' AND password ='$password'");
    $user = mysqli_fetch_assoc($query);

    var_dump($user);
    if(!empty($user)){
        $adres = "two.php";
        header("Location: $adres");
    } else {
        echo "Error";
    }};
?>