Private Sub Sum()
IF Text1.Text <> "" And Text2.Text <> "" Then
MessageBox.Show(Text1.Text + Text2.Text)
End
End Sub
Private Sub Text1_TextChanged(sender As Object, e As EventArgs) Handles Text1.TextChanged
Sum()
End Sub
Private Sub Text2_TextChanged(sender As Object, e As EventArgs) Handles Text2.TextChanged
Sum()
End Sub