Cannot modify header information

Warning (2): Cannot modify header information - headers already sent by (output started at C:\xampp\htdocs\aplikacja\app\controllers\components\swift_mailer.php:1) [CORE\cake\libs\controller\controller.php, line 640]

Code | Context

$status    =    "Location: http://localhost/fagp/pages/form_ok"

header - [internal], line ??
Controller::header() - CORE\cake\libs\controller\controller.php, line 640
Controller::redirect() - CORE\cake\libs\controller\controller.php, line 621
ContactsController::add() - APP\controllers\contacts_controller.php, line 35
Object::dispatchMethod() - CORE\cake\libs\object.php, line 115
Dispatcher::_invoke() - CORE\cake\dispatcher.php, line 227
Dispatcher::dispatch() - CORE\cake\dispatcher.php, line 194
[main] - APP\webroot\index.php, line 88

<?php 
// File -> app/controllers/components/swift_mailer.php
//http://bakery.cakephp.org/articles/view/updated-swiftmailer-4-xx-component-with-attachments-and-plugins

/** 
 * SwiftMailer 4.03 Component
 * 
 * @author Matt Huggins
 * @version 2.21
 * @license MIT
 * @category Components
 * @modifiedby d3f_l3pp4rd
 */

function add() {
        if (!empty($this->data)) {
            $this->Contact->create();
            if ($this->Contact->save($this->data)) {
                $this->Session->setFlash(__('The Contact has been saved', true));
                $this->contact($this->data); 
                $this->redirect(array('controller'=>'pages','action'=>'form_ok'));
                
                }
                
             else {
                $this->Session->setFlash(__('The Contact could not be saved. Please, try again.', true));
            }
        }
    }

 
        $this->SwiftMailer->smtpHost = 'tutaj jest host;
       // $this->SwiftMailer->smtpPort = 465;
        $this->SwiftMailer->smtpUsername = 'login';
        $this->SwiftMailer->smtpPassword = 'haslo';

        $this->SwiftMailer->sendAs = 'html';
        $this->SwiftMailer->from = 'adres_email_smtpl';
        $this->SwiftMailer->fromName = 'Automat';
        $this->SwiftMailer->to = 'tutaj to wysylaml';
         
        
     
       $this->set('message', $data);
        
        try {
            if(!$this->SwiftMailer->send('kontakt', 'Kontakt ze strony xxx')) {
                foreach($this->SwiftMailer->postErrors as $failed_send_to) {
                    $this->log("Failed to send email to: $failed_send_to");
                }
            }
        }
        catch(Exception $e) {
              $this->log("Failed to send email: ".$e->getMessage());
        }
        $this->autoRender = false;
    } 

<p><?php __('Name'); ?>: <?php echo $message['Contact']['name'] ?></p>
<p><?php __('Email'); ?>: <?php echo $html->link($message['Contact']['email'],'mailto:'.$message['Contact']['email']) ?></p>
<p><?php __('Subject'); ?>: <?php echo $message['Contact']['subject'] ?></p>
<p><?php __('Message'); ?>: <?php echo $message['Contact']['message'] ?></p>