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");
                }
            }
        }