Private Sub InvoiceButton_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles InvoiceButton.Click
For Each row As DataGridViewRow In Me.DataGridView1.SelectedRows
Dim cust As Customer = TryCast(row.DataBoundItem, Customer)
If cust IsNot Nothing Then
cust.SendInvoice()
End If
Next
End Sub