Dim textBoxes = Me.Controls.OfType(Of TextBox)()
For Each txtbox In textBoxes
AddHandler txtbox.LostFocus, AddressOf txtLostFocus
Next
one handler for all txtbox'es.
Private Sub txtLostFocus(sender As Object, e As System.EventArgs)
Try
CustomerDataContext1.SubmitChanges()
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
End sub