Php confirmation email to two emails?

[Pam D]

I want to send confirmation email to 2 differnet email boxes.
this is the code sending to one box:
$this->email->to($em);
and what should be the code sending same email to one more email box (example: mymail@gmail. com)

more details:
1,class Register extends Controller
2,
{
$this->load->library('email');
//$config['mailtype'] = 'html';
//$this->email->initialize($config);

$this->email->from('[email protected]', 'Site team');
$this->email->to($em);

$this->email->subject('Welcome');
$msg = 'You have registered';

$this->email->message($msg);

$this->email->send();
}
thanks