if($narrow_brand) {
            if(!empty($where_query)) $where_query = "WHERE Brand='".$narrow_brand."'";
            else $where_query = " AND Brand='".$narrow_brand."'";
        }

        if ($narrow_position)) {
            if(!empty($where_query)) $where_query = "WHERE Position='".$narrow_position."'";
            else $where_query = " AND Brand='".$narrow_position."'";
        }

        $query = "SELECT * FROM tbl ".$where_query;