/**
  * Change the session type for a submission.
  */
 function changeSessionType($args, $request)
 {
     $paperId = $request->getUserVar('paperId');
     $this->validate($request, $paperId);
     $conference =& $request->getConference();
     $schedConf =& $request->getSchedConf();
     $submission =& $this->submission;
     $sessionType = $request->getUserVar('sessionType');
     TrackDirectorAction::changeSessionType($submission, $sessionType);
     $request->redirect(null, null, null, 'submission', $paperId);
 }