function _storeHbreak()
    {
        // Return if the user hasn't specified pagebreaks
        if (empty($this->_hbreaks)) {
            return;
        }

        // Sort and filter array of page breaks
        $breaks = $this->_hbreaks;
        sort($breaks, SORT_NUMERIC);
        if ($breaks[0] == 0) { // don't use first break if it's 0
            array_shift($breaks);
        }

        $record  = 0x001b;               // Record identifier
        $cbrk    = count($breaks);       // Number of page breaks
        if ($this->_BIFF_version == 0x0600) {
            $length  = 2 + 6*$cbrk;      // Bytes to follow
        } else {
            $length  = 2 + 2*$cbrk;      // Bytes to follow
        }

        $header  = pack("vv", $record, $length);
        $data    = pack("v",  $cbrk);

        // Append each page break
        foreach ($breaks as $break) {
            if ($this->_BIFF_version == 0x0600) {
                $data .= pack("vvv", $break, 0x0000, 0x00ff);
            } else {
                $data .= pack("v", $break);
            }
        }

        $this->_prepend($header.$data);
    }