function OnLoadPageData()
 {
     /* @var $match_manager MatchManager */
     /* @var $editor TournamentEditControl */
     # get id of Match
     $i_id = $this->match_manager->GetItemId();
     if (!$i_id) {
         return;
     }
     # no need to read if redisplaying invalid form
     if ($this->IsValid()) {
         $this->match_manager->ReadByMatchId(array($i_id));
         $this->tournament = $this->match_manager->GetFirst();
         if ($this->tournament instanceof Match) {
             $this->b_user_is_match_owner = AuthenticationManager::GetUser()->GetId() == $this->tournament->GetAddedBy()->GetId();
             $this->b_is_tournament = $this->tournament->GetMatchType() == MatchType::TOURNAMENT;
         } else {
             return;
         }
     }
     if ($this->b_user_is_match_admin or $this->b_user_is_match_owner) {
         # Get all seasons
         # Don't filter by match type at this point because we want to know what other types of match the seasons support.
         # If it's tournaments only, they'll be treated differently.
         require_once 'stoolball/season-manager.class.php';
         $season_manager = new SeasonManager($this->GetSettings(), $this->GetDataConnection());
         $season_dates = Season::SeasonDates($this->tournament->GetStartTime());
         $season_manager->FilterByDateStart($season_dates[0]);
         $season_manager->FilterByDateEnd($season_dates[1]);
         $season_manager->ReadSeasonSummaries(array($this->tournament->GetPlayerType()));
         $this->editor->Seasons()->SetItems($season_manager->GetItems());
         unset($season_manager);
     }
 }