public void CreateSalesTransaction() { if (!CheckData()) { string customerID = CustomerIDTextBox.Text; string saleDate = GetSalesDate(); string invoiceNumber = "S" + CreateInvoiceNumber(); Dictionary<int, double> soldProducts = GetSalesInformation(); DataManager dataManager = new DataManager(connectionString); foreach (KeyValuePair<int, double> pair in soldProducts) { dataManager.SaveSaleData(customerID, pair.Key.ToString(), pair.Value.ToString(), saleDate, invoiceNumber); dataManager.UpdateProductStatus(pair.Key.ToString(), saleDate); } string totalSale = TotalLabel.Text; string salesTax = TaxLabel.Text; string grandTotal = GrandTotalLabel.Text; dataManager.SaveInvoiceData(invoiceNumber, totalSale, salesTax, saleDate, customerID, grandTotal); SalesInvoice salesInvoice = new SalesInvoice(); salesInvoice.InvoiceNumberValue = invoiceNumber; salesInvoice.CustomerIDValue = customerID; salesInvoice.InvoiceDollarValue = invoiceNumber; salesInvoice.Show(); } else { MessageBox.Show("Either the customer ID is blank, you did not select a product, or there is no total"); } }