public function updatepositionAction()
 {
     if ($params = $this->getRequest()->getPost()) {
         if (empty($params['latitude']) or empty($params['longitude']) or empty($params['device_uid'])) {
             return;
         }
         $device = new Push_Model_Iphone_Device();
         $device->find($params['device_uid'], 'device_uid');
         if (!$device->getId()) {
             $device->setDeviceUid($params['device_uid']);
         }
         $device->setLastKnownLatitude($params['latitude'])->setLastKnownLongitude($params['longitude'])->save();
         $messages = $device->findNotReceivedMessages();
         if ($messages->count() > 0) {
             foreach ($messages as $message) {
                 $instance = $message->getInstance('iphone');
                 $instance->setMessage($message);
                 if ($instance->isInsideRadius($device->getLastKnownLatitude(), $device->getLastKnownLongitude())) {
                     $instance->isDev($isDev)->sendMessage($device);
                 }
             }
         }
         die('done');
     }
 }