$username = $_GET['user'];

    $password = $_GET['password'];

    $db = new mysqli('localhost', 'dbuser', 'dbpass', 'mydatabase');

    $result = $db->("SELECT * FROM Users WHERE Username='$username' AND

    Password='$password'");

    if (!empty($result)){

        print "Hello $username. Logged you in successfully!";

    }

    $db->close();

$username = $_GET['user'];

$password = $_GET['password'];

$db = new mysqli('localhost', 'dbuser', 'dbpass', 'mydatabase');

if ($mysqli->connect_error) {

    die('Error : ('. $mysqli->connect_errno .') '. $mysqli->connect_error);

}    

    $result = $db->query("SELECT * FROM Users WHERE Username='$username' AND

    Password='$password'");

    if (!empty($result)){

        print "Hello $username. Logged you in successfully!";

    }

    $db->close();