I have a php authentication script and everything works fine, but I'm very unsure about the way I programmed it (I hardcoded some things). I was hoping stack could look through this and point out any potential problems. Here's the script:<?phprequire_once 'Bcrypt.php';class Mysql {    private $conn;    function __construct() {        $this->conn =  new PDO('mysql:host=***;dbname=***;charset=UTF-8','***','***') or                       die('There was a problem connecting to the database.');    }    function verify_Username_and_Pass($un, $pwd) {        ini_set('display_errors', 'On');        error_reporting(E_ALL | E_STRICT);        $query = SELECT *                FROM Conference                WHERE Username = :un;        $stmt = $this->conn->prepare($query);        $stmt->bindParam(':un', $un);        //$stmt->bindParam(':pwd', $pwd);        $stmt->execute();        $row = $stmt->fetchAll();        $hash = $row[0][Password];        $is_correct = Bcrypt::check($pwd, $hash);        if ($is_correct) {            // User exist            $firstName = $row[0][First Name];            $_SESSION[FirstName] = $firstName;            return true;            $stmt->close();        }        else {            // User doesn't exist            return false;            $stmt->close();        }    }}?>So how does it look?
PHP Login Authentication with BCrypt
php;sql;mysql;pdo