Hii,
Try this:
require_once("./pdf/dompdf_config.inc.php");
$files = glob("./pdf/include/*.php");
foreach($files as $file) include_once($file);
$html =
'<html><body>'.
'<p>Put your html here, or generate it with your favourite '.
'templating system.</p>'.
'</body></html>';
$dompdf = new DOMPDF();
$dompdf->load_html($html);
$dompdf->render();
$output = $dompdf->output();
file_put_contents('Brochure.pdf', $output);
Only difference here is that all of the files in the include directory are included.
Other than that my only suggestion would be to specify a full directory path for writing the file rather than just the filename.