ActionScript for Flash MX: The Definitive Guide, 2nd Edition By Colin Moock
Chapter 18. ActionScript Language Reference
Button._visible Property
Flash 6
whether the button is shown or hidden
read/write
theButton._visible
Description
The Boolean _visible property indicates whether theButton is shown (true) or hidden (false). We use _visible as a quick means of hiding a button from view. Hidden buttons can still be controlled via ActionScript; they simply are not displayed on screen. However, a hidden button cannot receive focus or user input, so its events do not get triggered.
Button._visible is directly analogous to MovieClip._visible; see that property entry for full details.