public function _runAction($action)
 {
     //handle back action here
     //unset session variable for current step
     //change action name
     //go to process in normal way
     if ($action == 'backAction') {
         switch ($this->session->step) {
             case 2:
                 if (@$this->session->uploadSerialized) {
                     $this->upload->unserialize($this->session->uploadSerialized);
                     $this->upload->removeFiles();
                 }
                 unset($this->session->path);
                 unset($this->session->fieldsMap);
                 unset($this->session->importOptions);
                 $action = 'indexAction';
                 break;
             case 3:
                 unset($this->session->fieldsValue);
                 $action = 'assignAction';
                 break;
             case 4:
                 $action = 'defineAction';
                 break;
         }
         $this->getRequest()->setActionName(str_replace('Action', '', $action));
     }
     parent::_runAction($action);
 }