public void AddNewNode(string nodeName, string parentNodeType)
        {
            Journal journal;
            switch (parentNodeType)
            {
                case JsTreeNodeType.Subjects:
                    var subject = new Subject {SubjectName = nodeName};
                    JournalContext.Subjects.InsertOnSubmit(subject);
                    JournalContext.SubmitChanges();
                    break;
                case JsTreeNodeType.PupilClass:
                    journal = new Journal {JournalName = nodeName, Year = DateTime.Now.Year};
                    JournalContext.Journals.InsertOnSubmit(journal);
                    JournalContext.SubmitChanges();
                    break;
                //case JsTreeNodeType.Pupil:
                //    journal = JournalContext.Journals.First(j => j.JournalName == parentId);
                //    journal.Pupils.Add(new Pupil(){JournalID = journal.JournalID});
                //    break;
                case JsTreeNodeType.Default:
                    break;

            }
        }
 partial void DeleteSubject(Subject instance);
 partial void InsertSubject(Subject instance);
 partial void UpdateSubject(Subject instance);
partial         void InsertSubject(Subject instance)
        {
            if (!Subjects.Contains(instance))
                ExecuteDynamicInsert(instance);
        }