public function getPdt($transactionID)
    {
        $this->transactionID = $transactionID;
        
        // Now we need to ask PayPal to tell us if it sent this notification
        $pdtResponse = $this->_postData($this->pdtURL, array('cmd' => '_notify-synch', 'tx' => $transactionID, 'at' => $this->pdtToken));
        if ($pdtResponse === FALSE) { // Bail out if we have an error.
            return FALSE;
        }

        // Phew! We have a valid PDT transaction, log it.
        $this->_logTransaction('PDT', 'SUCCESS', 'Parsing complete', $pdtResponse);
        return $pdtResponse;
    }