public function actionChooseCopy()
 {
     /// this is the DO action
     if (isset($_POST['ClassInfo'])) {
         if (ClassInfo::copyClass($_POST['ClassInfo']['id'], ClassSession::savedSessionId())) {
             $this->redirect(array('index'));
         }
     }
     // TODO: display any errors set from the copyclass function
     $this->render('choose_copy', array('fromsession' => ClassSession::previousPublic()));
 }