/**
  * Cancel Bill action
  *
  * @Secure(roles="ROLE_USER")
  */
 public function cancelbillAction(Intervention $entity)
 {
     $em = $this->getDoctrine()->getManager();
     if ($entity->getMustBeBilled()) {
         if ($entity->getBill() !== null) {
             // 	annuler la facture existante
             $bill = $entity->getBill();
             $bill->setIntervention();
             $bill->setState(-1);
             $entity->setBill();
             $em->persist($bill);
         } elseif ($entity->getExternalBill() !== null) {
             $entity->setExternalBill();
         }
     }
     $entity->setMustBeBilled(null);
     $em->persist($entity);
     $em->flush();
     return $this->redirect($this->generateUrl('intervention_redirect', array('id' => $entity->getId(), 'act' => 'show')));
 }