private void buttonDeleteCustomer_Click(object sender, EventArgs e) { DialogResult dialogResult = MessageBox.Show("Delete customer?", "Checkbox", MessageBoxButtons.YesNo); if (dialogResult == DialogResult.Yes) { try { var cell = this.dataGridViewCustomerUserControl.SelectedCells[0]; int clickedCellID = Reader.LoadCustomersDataTable().Rows[cell.RowIndex].Field <int>("CustomerID"); Deleter.DeleteCustomer(clickedCellID); MessageBox.Show("Customer deleted!"); SetUpDefaultDataTableCustomers(); } catch (Exception) { MessageBox.Show("This customer have an existing order, and cannot be deleted"); } } }