Dim answer As DialogResult = _
  MessageBox.Show("VB.NET使ってる?", "質問", MessageBoxButtons.YesNo, MessageBoxIcon.Question)

If answer = DialogResult.Yes Then
  MessageBox.Show("よろしい。", "( ´∀`)")
Else
  MessageBox.Show("時代遅れ。氏ね", "(゚Д゚)")
End If