Php mailer in codeigniter

i want to send a email when register a user. i'm using the xampp, codeigniter and phpMailer. when i submit the registration form it was an error called

Message was not sent 
PHPMailer Error: SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting
Registration Successfully !

here is my code(controller)

session_start(); //we need to start session in order to access it through CI

//The controller class is extends CI_Contoller
Class User_Authentication extends CI_Controller {

public function __construct() {
parent::__construct();

// Load form helper library

$this->load->helper('form');

// Load form validation library
$this->load->library('form_validation');
$this->load->library('my_phpmailer');

// Load session library
$this->load->library('session');

// Load database

$this->load->model('login_database');
}

// Show login page
public function index() {
$this->load->view('user_site/login_form');
}

// Show registration page
public function user_registration_show() {

$this->load->view('user_site/registration_form');
}

// Validate and store registration data in database
public function new_user_registration() {

// Check validation for user input in SignUp form
$this->form_validation->set_rules('firstname', 'First Name', 'trim|required|xss_clean');
$this->form_validation->set_rules('lastname', 'Last Name', 'trim|required|xss_clean');
$this->form_validation->set_rules('email', 'Email', 'trim|required|xss_clean');

$this->form_validation->set_rules('password', 'Password', 'trim|required|xss_clean|md5');
if ($this->form_validation->run() == FALSE) {
$this->load->view('user_site/registration_form');
//    $this->load->view('register');
} else {
$data = array(
'firstname' => $this->input->post('firstname'),
'lastname' => $this->input->post('lastname'),
'email' => $this->input->post('email'),
'password' => $this->input->post('password'),

'address' => $this->input->post('address'),
'contact_no' => $this->input->post('contact_no')
);
$result = $this->login_database->registration_insert($data);
if ($result == TRUE) {
$data['message_display'] = 'Registration Successfully !';

$mail = new PHPMailer();
            $mail->IsSMTP();
            $mail->Mailer = 'smtp';

            $mail->SMTPAuth = true;
            $mail->Host = 'smtp.gmail.com'; // "ssl://smtp.gmail.com" didn't worked
            $mail->Port = 465;
            $mail->SMTPSecure = 'ssl';
            // or try these settings (worked on XAMPP and WAMP):
            // $mail->Port = 587;
            // $mail->SMTPSecure = 'tls';


            $mail->Username = "ashik@gmail.com";

            $mail->Password = "zswedfr";

            $mail->IsHTML(true); // if you are going to send HTML formatted emails
            $mail->SingleTo = true; // if you want to send a same email to multiple users. multiple emails will be sent one-by-one.

            $mail->From = "ashik@gmail.com";
            $mail->FromName = "ABC";

                $address = $_POST['email'];
                $mail->AddAddress($address, "Guest");



            $mail->Subject = "ABC Email validation ";

            $mail->Body ="ABC Email validation";

            if(!$mail->Send()){

                echo "Message was not sent 
PHPMailer Error: " . $mail->ErrorInfo;
            }else{

                echo "sucfdt  " ;
            }
$this->load->view('user_site/login_form', $data);
} else {
$data['message_display'] = 'Email already exist!';
//$this->load->view('user_site/registration_form', $data);
$this->load->view('register');
}
}
}

this is the php file in library

if ( ! defined('BASEPATH')) exit('No direct script access allowed');

class My_PHPMailer {
    public function My_PHPMailer() {
        require_once('PHPMailer/PHPMailerAutoload.php');

    }
}