if(isset($_POST["login"])){
        $username = $_POST["username"];
        $password = $_POST["password"];
        $password_hashed = password_hash($password,PASSWORD_DEFAULT);
        $SQL = "SELECT `username`, `password` FROM `users` WHERE `username` = ?";
        if($stmt = $conn->prepare($SQL)){
            $stmt->bind_param("s", $username);
            $stmt->bind_result($username, $password_hashed);
            if($stmt->execute()){
                $stmt->store_result();
                if($stmt->num_rows == 1){
                    $stmt->fetch();
                    if(password_verify($password, $password_hashed)){
                        echo "U bent nu ingelogd.";
                    } else {
                        echo "Inloggen mislukt.";
                    }
                }

            }
        }
    }