login.php

<?php

require("config.php");

if (!empty($_POST)) {

    $query = "SELECT * FROM pengguna WHERE username = :png";

    $query_params = array(
        ':png' => $_POST['username']
    );

    try {
        $stmt   = $db->prepare($query);
        $result = $stmt->execute($query_params);
    }
    catch (PDOException $ex) {
        $response["sukses"] = 0;
        $response["pesan"] = "Database Error. Silahkan coba lagi!";
        die(json_encode($response));

    }
    $validated_info = false;

    $row = $stmt->fetch();
    if ($row) {

        $password = md5($_POST['password']);
        if ($password === $row['password']) {
            $login_ok = true;
        }
    }

    // If the user logged in successfully, then we send them to the private members-only page
    // Otherwise, we display a login failed message and show the login form again
    if ($login_ok) {
        $response["sukses"] = 1;
        $response["pesan"] = "Login Berhasil!";
        die(json_encode($response));
    } else {
        $response["sukses"] = 0;
        $response["pesan"] = "Identitas Invalid!";
        die(json_encode($response));
    }
} else {
?>
        <h1>Login</h1>
        <form action="login.php" method="post">
            Username:<br />
            <input type="text" name="username" placeholder="username" />
            <br /><br />
            Password:<br />
            <input type="password" name="password" placeholder="password"/>
            <br /><br />
            <input type="submit" value="Login" />
        </form>
        <a href="daftar.php">Daftar</a>
    <?php
}

?>