function flush()
 {
     $ts = !$this->getLastBuildDate() ? time() : $this->getLastBuildDate();
     HTTPResponse::setLastModified($ts);
     $ctype = preg_match('/Mozilla/i', $_SERVER['USER_AGENT']) ? 'text/xml' : 'application/rss+xml';
     header('Content-Type: ' . $ctype . '; charset="' . $this->CharSet . '"', true);
     $this->stream = new StdOutWriter(false);
     $this->compile();
     $this->stream->dispose();
 }