if (isset($_POST['userid']) && isset($_POST['password'])){

$username = $_POST['userid'];
$password = crypt($_POST['password'],'34l5kj');


    $query = "SELECT * FROM users WHERE name =:username and pass=:password";
$db->query($query);
$db->bind(':username', $username);
$db->bind(':password', $password);
$db->execute();
$data = $db->single();

            $_SESSION['valid_user'] = $username;
            $_SESSION['user_id'] = $data['id'];
            $_SESSION['pwd']=$_POST['password'];