protected function exportFormStep(Request $request, $alias)
    {
        $exportManager = $this->get('chill.main.export_manager');
        
        // check we have data from the previous step (export step)
        $data = $this->get('session')->get('centers_step', null);
        
        if ($data === null) {
            
            return $this->redirectToRoute('chill_main_export_new', array(
               'step' => $this->getNextStep('export', true),
               'alias' => $alias
               ));
        }
        
        $export = $exportManager->getExport($alias);
                
        $form = $this->createCreateFormExport($alias, 'export', $data);
        
        if ($request->getMethod() === 'POST') {
            $form->handleRequest($request);
            if ($form->isValid()) {
                
                $this->get('logger')->debug('form export is valid', array(
                      'location' => __METHOD__));
                
                // store data for reusing in next steps
                $data = $form->getData();
                $this->get('session')->set('export_step_raw', 
                      $request->request->all());
                $this->get('session')->set('export_step', $data);
                
                //redirect to next step
                return $this->redirect(
                      $this->generateUrl('chill_main_export_new', array(
                         'step' => $this->getNextStep('export'),
                         'alias' => $alias
                      )));
            } else {
                $this->get('logger')->debug('form export is invalid', array(
                      'location' => __METHOD__));
            }
        }
        
        return $this->render('ChillMainBundle:Export:new.html.twig', array(
            'form' => $form->createView(),
            'export_alias' => $alias,
            'export' => $export
        ));
    }