function setLetterTopics($letter_id, $topics_ids)
 {
     global $application;
     if (!is_array($topics_ids)) {
         $topics_ids = array($topics_ids);
     }
     $tables = $this->getTables();
     $ntables = modApiFunc('Newsletter', 'getTables');
     $ltable = 'newsletter_topics';
     $lcolumns =& $ntables[$ltable]['columns'];
     $dquery = new DB_Delete($ltable);
     $dquery->WhereValue($lcolumns['letter_id'], DB_EQ, $letter_id);
     $application->db->getDB_Result($dquery);
     $iquery = new DB_Multiple_Insert($ltable);
     $iquery->setModifiers(DB_IGNORE);
     $iquery->setInsertFields(array('letter_id', 'topic_id'));
     foreach ($topics_ids as $topic_id) {
         $iquery->addInsertValuesArray(array('letter_id' => $letter_id, 'topic_id' => $topic_id));
     }
     $application->db->getDB_Result($iquery);
 }