public function getStatuses()
    {
        $schedules = clone $this->getCollection()
            ->setOrder('status', Zend_Db_Select::SQL_ASC);
        $schedules->getSelect()
            ->group('status')
            ->reset(Zend_Db_Select::COLUMNS)
            ->columns('status');
        $statuses = $schedules->getConnection()
            ->fetchCol($schedules->getSelect());
        $statusArray = array();
        foreach ($statuses as $status) {
            $statusArray[$status] = $status;
        }
        return $statusArray;
    }