private void UpdateButton_Click(object sender, EventArgs e) { if (DepartmentNameTextBox.Text == "") { MessageBox.Show("Please, enter a department name."); } else { int r = controllerObj.A_UpdateDepartment(Convert.ToInt32(DepartmentsComboBox.SelectedValue), DepartmentNameTextBox.Text.ToString()); if (r > 0) { MessageBox.Show("Department updated successfully."); DataTable dt1 = controllerObj.SelectDepIDsNames(); DepartmentsComboBox.DataSource = dt1; DepartmentsComboBox.DisplayMember = "Name"; DepartmentsComboBox.ValueMember = "DepID"; } else { MessageBox.Show("Error in updating department."); } } }