Full Screen Mode / Half Screen Mode Toggle.

    Keys:
         F1 (pick Full Screen)

         or use the Quick Keys

         F9 or Alt-Z

    Action:
         Toggles the Display Window to either Full Screen or Half Screen
         mode. In Half Screen mode you are able to move the window up and
         down using the Shift Up/Dn Arrow Keys. Also if the screen is in
         half-screen mode and the Auto-Lookup feature is turned ON the
         window will position itself away from the search word (when
         popped-up).