private void detach_CourseInfo(CourseInfo entity)
		{
			this.SendPropertyChanging();
			entity.TeacherInfo = null;
		}
 partial void DeleteCourseInfo(CourseInfo instance);
 partial void UpdateCourseInfo(CourseInfo instance);
 partial void InsertCourseInfo(CourseInfo instance);
		private void attach_CourseInfo(CourseInfo entity)
		{
			this.SendPropertyChanging();
			entity.ExperimentInfo = this;
		}
 protected bool IsBooked(StudentInfo student, CourseInfo course)
 {
     if (LabDB.CourseBookInfo.FirstOrDefault(d => d.StudentInfo == student && d.CourseArrange.CourseInfo == course) != null)
         return true;
     else return false;
 }