static function add_category($id)
 {
     $contents = array();
     $category = MObject::get('category', $id);
     if ($category && sizeof($category->get_contents()) > 0) {
         $i = 0;
         foreach ($category->get_contents() as $content) {
             $title = '';
             $title .= '<a href="index.php?module=content&object=' . MPut::id($content->get_id()) . '">' . MPut::html($content->get_title()) . '</a>';
             $title .= '<br />';
             $title .= '<small>(' . MPut::text($content->get_address()) . ')</small>';
             $contents[$i] = array('title' => $title, 'text' => substr(strip_tags($content->get_text()), 0, 100) . ' ... <br /><br /><a href="index.php?module=content&object=' . intval($content->get_id()) . '"><small>read more &gt;&gt;</small></a>', 'lat' => $content->get_lat(), 'lng' => $content->get_lng(), 'category' => $category->get_name());
             if ('event' == $content->get_type()) {
                 $contents[$i]['start'] = $content->get_start();
                 $contents[$i]['end'] = $content->get_end();
             }
             $i++;
         }
     }
     return $contents;
 }