private void deleteExamPlan()
 {
     try
     {
         string ExamPlanID = context.Request.Form.Get("ExamPlanID");
         PlanService planService = new PlanService();
         ExamPlan examPlan = planService.getExamPlanByID(ExamPlanID);
         examPlan.CouresSet = null;
         planService.save(examPlan);
         planService.del(examPlan);
         context.Response.Write("1");
     }
     catch (Exception e)
     {
         context.Response.Write("0");
     }
 }