private void btnsave_Click(object sender, EventArgs e) { try { int empidlength = txtemployeeid.Text.Length; bool isvalidated = validatefields(); if (isvalidated) { if (empidlength != 6) { throw new Exception("Employee id should be 6 digit number"); } Lecturer lecturer = new Lecturer(); lecturer.lecturername = txtlecturername.Text; lecturer.center = combocenter.SelectedItem.ToString(); lecturer.employeeid = txtemployeeid.Text; lecturer.building = combobuilding.SelectedItem.ToString(); lecturer.faculty = combofaculty.SelectedItem.ToString(); lecturer.level = Convert.ToInt32(combolevel.SelectedItem.ToString()); lecturer.department = combodepartment.SelectedItem.ToString(); lecturer.rank = txtrank.Text; string message = LecturerController.AddLecturer(lecturer); MessageBox.Show(message); clear(); } else { MessageBox.Show("please fill in all fields!"); } } catch (NullReferenceException nre) { MessageBox.Show("please fill in all fields!"); } catch (Exception ex) { MessageBox.Show(ex.Message); } }