Rick Brandt said:
Set the TimerInterval to 500 (or whatever) and in the Timer event have
code...
Me.TextBoxName.Visible = Not Me.TextBoxName.Visible
(use with caution as flashing graphics are generally frowned upon)
I believe Tom was asking about a message box.
While it's probably possible to do this with a message box, it would take a
lot of API calls. It's simpler to create your own form that simulates the
message box, and then use the technique shown above.