Shows (displays or makes visible) the given widget object
and all its descendents. This is only needed for initial display
(a widget is not displayed unless its parent is, dialogs are
created undisplayed by default) and redisplaying a widget
after it has been hidden.
Usually only used on a dialog ancestor (in some form).
Removes all or a single level of application locking.
When the stack level returns to 0, the application becomes
active and the watch cursor is removed.
Without options, VtUnLock clears all levels of application locks.