$db = JFactory::getDbo();

				  $arr_catids = array();

				  $catsql = "SELECT cat.id, cat.title as name, cat.params FROM #__categories  as cat WHERE cat.extension='com_jevents' ";

			           $db->setQuery($catsql);

			           $allcat_catids = $db->loadObjectList('id');

				   

				    $db = JFactory::getDbo();

				    $db->setQuery("Select catid from #__jevents_catmap  WHERE evid = " . $event->ev_id());

				    $allcat_eventcats = $db->loadColumn();



				    $allcats = array();

				    foreach ($allcat_eventcats as $catid)

				    {

					    if (isset($allcat_catids[$catid]))

					    {

						    $allcats[] = $allcat_catids[$catid]->name;

					    }

				    }

				    $categories = implode(", ", $allcats);