http_header('Content-Type' => 'application/pdf' );
http_header('Content-Length' => length($pdf) );
http_header('Cache-control' => 'max-age=60' );
http_header('Content-Type' => 'application/pdf' );
http_header('Content-Length' => length($pdf) );
http_header('Cache-control' => 'max-age=60' );