I have 2 listboxes side by side where the user can move an item from left to
right or vice versa by double clicking the item or clicking on a button(s)
between the two listboxes.  I want to enable to disable the move left or
move right buttons as determined by the number of items in the listbox.

Example.  I have no items in the right hand list box so I don't want the
move left button to be enabled.  As soon as an item is moved to the right
hand listbox then I would like the return button to be enabled.  As the
MoveListItem can be called in several ways, I am trying to think of a clean
way to enable or disable without duplicating the code.

What is the best way to do this?

Bill