PHP: Getting insert confirmation on prepared statement

I am a newbie to prepared statements and trying to get something simple to work.

This is my DB table:

`unblocker_users` (
  `uno` bigint(20) NOT NULL AUTO_INCREMENT,
  `user_email` varchar(210) DEFAULT NULL,
  `pw_hash` varchar(30) DEFAULT NULL,
  `email_confirmed` tinyint(4) DEFAULT NULL,
  `total_requests` bigint(20) DEFAULT NULL,
  `today_date` date DEFAULT NULL,
  `accessed_today` tinyint(4) DEFAULT NULL,)

and this is my function to insert some test data

function add_new_user($e_mail1)
    {
    require_once "db.php";

$stmt = $mysqli->prepare("INSERT INTO unblocker_users VALUES ('',?, ?,0,0,?,0)");
$stmt->bind_param('sss', $e_mail1, 开发者_如何学C$this->genRandomString(1),$this->today_date()); 

$stmt->execute();

$stmt->close(); 
// ####### Below line is giving an error ########
$done = $stmt->affected_rows;

return $done;
    }

As you can see above, i have marked the line that is giving me an error.

Warning: unblocker_class::add_new_user() [unblocker-class.add-new-user]: Property access is not allowed yet in...

Where did I go wrong? How can i get some sort of confirmation that a row has been inserted successfully?

Thanks!

you close the prepared statement BEFORE you want to access its affected rows

$done = $stmt->affected_rows;
$stmt->close(); 

return $done;