Create a Windows Forms application to support data maintenance (CRUD functionality) of Invoices per Vendor in the Payables database. 
Make use of the Connection, Transaction, Command, and DataReader objects of the ADO.NET SQLClient Provider, 
not DataSets, DataTables, DataAdapters or the Configuration Wizard.

The user has to select a Vendor and then view, add, edit or delete Invoice records for the selected vendor. 
Changes have to be saved before the user can select another vendor.

Feel free to make use of a combination of UI controls such as Grids, TextBoxes, ComboBoxes, etc. 