enable-top

Enables or disables an entire top-level menu in a menu bar. If the menu bar is not already associated with a frame, this metho as no affect.

• (send a-wx:menu-bar enable-top n on?) -> void
      n : small integer
      on? : boolean

  If on? is #f, the nth menu of the menu bar is disabled, otherwise it is enabled. The menus are numbered from 0.