>>
>>I assume you mean the nTimeout parameter. But the answer to your question is, "No." What's the point in using a timeout if you want to require that the user presses the key?
>
>I want user to click on Ok button/press the key or the messagebox clearing by itself. But I don't want the messagebox to be visually cleared but yet prevent user from continue working. The addition of this undocumented parameter did the job.

Sorry, I misunderstood that your goal was to make the messagebox modal.