public function deleteRecord($index)
    {
        if (isset($this->records[$index])) {
            $this->fileLength -= ($this->records[$index]->getContentLength() + 4);
            $count = count($this->records) - 1;
            for ($i = $index; $i < $count; ++$i) {
                $this->records[$i] = $this->records[$i + 1];
            }
            unset($this->records[count($this->records) - 1]);
            $this->_deleteRecordFromDBF($index);
        }
    }