public function create($period)
 {
     $balance = new GLBalance();
     // Set the identifier field - this is used by bulk_insert
     // to count the distinct rows that should be inserted
     $balance->identifierField = "glcentre_id||'-'||glaccount_id";
     $balance->orderby = '';
     $balances = new GLBalanceCollection($balance);
     $balances->setTablename('gl_year_to_date_summary');
     $balances->orderby = '';
     $sh = new SearchHandler($balances, false);
     $fields = array($period->id . ' as glperiods_id');
     $fields = array('glcentre_id', 'glaccount_id', 'glperiods_id', 'mth_actual', 'ytd_actual', 'usercompanyid', "'" . EGS_USERNAME . "' as createdby", "'" . EGS_USERNAME . "' as alteredby");
     $sh->setFields($fields);
     $sh->addConstraint(new Constraint('year', '=', $period->year));
     $sh->addConstraint(new Constraint('period', '=', $period->period));
     //	Insert the year to date values
     $result = $this->bulk_insert(array('glcentre_id', 'glaccount_id', 'glperiods_id', 'mth_actual', 'ytd_actual', 'usercompanyid', 'createdby', 'alteredby'), $sh);
     return $result;
 }