Facebook fql query using LIMIT and ORDER BY sorting ASC or DESC

function get_photos_by_album_id($album_id){
if($album_id)
        $fql            =   'SELECT pid,src_big,owner,link,position,created,caption,src FROM photo WHERE aid="'.$album_id.'" ORDER BY created DESC LIMIT 0,40';
	 $param  =   array(
                'method'    => 'fql.query',
                'query'     => $fql,
                'callback'  => ''
            );
            $fqlResult   =   $this->facebook->api($param);
		return $fqlResult;
 
}