protected function enabled($url) {
		$web=Web::instance();
		$req=$web->request($url);
		$found=FALSE;
		if ($req && $req['body']) {
			// Look for pingback header
			foreach ($req['headers'] as $header)
				if (preg_match('/^X-Pingback:\h*(.+)/',$header,$href)) {
					$found=$href[1];
					break;
				}
			if (!$found &&
				// Scan page for pingback link tag
				preg_match('/<link\h+(.+?)\h*\/?>/i',$req['body'],$parts) &&
				preg_match('/rel\h*=\h*"pingback"/i',$parts[1]) &&
				preg_match('/href\h*=\h*"\h*(.+?)\h*"/i',$parts[1],$href))
				$found=$href[1];
		}
		return $found;
	}