//Adds a new customer when the 'Add' button is clicked
        private void btnCustomerAdd_Click(object sender, EventArgs e)
        {
            CustomerWindow cw = new CustomerWindow();

            cw.ShowDialog();
            cmbBoxCustomerType.SelectedIndex = 0;
            ShowCustomers(Convert.ToString(cmbBoxCustomerType.SelectedIndex));
        }
        //Edit a selected customer record when the 'Edit' button is clicked
        private void btnCustomerEdit_Click(object sender, EventArgs e)
        {
            string customerRecord = Convert.ToString(listBoxCustomer.SelectedItem);         //Reads the selected item from the listbox as a string

            string[] customerID = customerRecord.Split(' ');                                //Split the strings into an array of strings, assuming the first array would be the customer's ID

            //Check is there any customer records in the listbox
            if (listBoxCustomer.Items.Count != 0)
            {
                CustomerWindow cw = new CustomerWindow(acc.AccountType, "Edit", customerID[1]);
                cw.ShowDialog();
                ShowCustomers(Convert.ToString(cmbBoxCustomerType.SelectedIndex));
            }
            else
            {
                MessageBox.Show("No Customer Selected !!", "Edit Customer Details", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }