txtQty.DataBindings.Add("Text", bsInvoiceDetails, "Detail_Quantity");

dsInvoiceDetails = new
dsInvoiceDetails.Tables.Add(dtInvoiceDetails);

bsInvoiceDetails.DataSource = dsInvoiceDetails;
bsInvoiceDetails.DataMember = "Invoice_Detail";

gridInvoiceDetails.DataSource = bsInvoiceDetails;
bnInvoiceDetails.BindingSource = bsInvoiceDetails;

bsInvoiceDetails.AddingNew += new AddingNewEventHandler(bsInvoiceDetails_AddingNew);

void bsInvoiceDetails_AddingNew(object sender, AddingNewEventArgs e)
    {
        try
        {
            InvoiceDetail id = new InvoiceDetail();
            id.InvoiceID = invoice.InvoiceID;   // Make sure we are hooked to this invoice.
            id.DetailDate = DateTime.Today;
            id.DetailQuantity = 0;
            id.DetailRate = 0;
            id.DetailTotal = 0;
            id.DetailDescription = "* New Detail Description *";

            e.NewObject = id;
        }
        catch (Exception ex)
        {
            ErrorManager em = new ErrorManager(ex, "InvoiceEditForm.cs", "bsInvoiceDetails_ListChanged", "Adding a new detail item", "sql");
        }
    }