private void Save()
        {
            try
            {
                if (isFormLoaded && _teacher != null)
                {
                    if (_teacher.Name.Length < 10 || _teacher.Name.Length > 100)
                    {
                        MessageBox.Show("Teacher Name character should be between 10 and 100.");
                        return;
                    }

                    if (_id == -1)
                    {
                        schoolMan.AddTeacher(_teacher);
                    }
                    else
                    {
                        schoolMan.UpdateTeacher(_teacher);
                    }
                }
                MessageBox.Show("Save Operation succeed.");
                btnSave.Enabled = false;
                btnCancel.Text  = "Close";
                return;
            }
            catch (Exception ex)
            {
                Logger.LogException(ex);
                MessageBox.Show("Save Operation failed.");
            }
        }