public function addJournalEntryImage($iDocumentId)
 {
     if ($this->iJournalEntryId === null) {
         $this->aUnsavedDocuments[] = $iDocumentId;
         return;
     }
     if (JournalEntryImagePeer::retrieveByPK($this->iJournalEntryId, $iDocumentId)) {
         return;
     }
     $oJournalEntryImage = new JournalEntryImage();
     $oJournalEntryImage->setJournalEntryId($this->iJournalEntryId);
     $oJournalEntryImage->setDocumentId($iDocumentId);
     return $oJournalEntryImage->save();
 }