title: MessageBox closed event
body: <p>I have MessageBox only with <code>Ok</code> button, although there's close button. But in code I can check only <code>DialogResult.Ok</code>.
  How should I check which button user had pressed?
  Only as <code>if (MessageBox("error") != DialogResult.Ok)</code> or there's another way?
  Is any event, that occures, when user closes MessageBox?</p>