public bool ScoreStudentCourse(Selection selectedSelection)
 {
     ISelectionDao selectionDao = new SelectionDao(sessionFactory);
     try
     {
         selectionDao.Update(selectedSelection);
         return true;
     }
     catch (Exception e) {
         return false;
     }
 }
 //允许对某一学年,有一学期,的学生打分
 public bool PermitScoreStudent(string studyYear, string term)
 {
     ISelectionDao selectionDao = new SelectionDao(sessionFactory);
     try
     {
         IList<Selection> selectionList = selectionDao.PermitSeletionScorePermit(studyYear,term);
         for (int i = 0; i < selectionList.Count; i++)
         {
             selectionList[i].selectionScorePermit = true;
             selectionDao.Update(selectionList[i]);
         }
         return true;
     }
     catch (Exception e) {
         return false;
     }
 }