>Thanks
>So what is the relationship between World and Display
>then?

Display is the bitmap (Form) which represents the display.  Modifying 
the Display does change what appears on the screen.

The World is a PasteUpMorph that contains cursors and all of the 
objects beneath it.  The World does contain a Canvas, which is 
responsible for drawing the morphs onto the Display.  But the World 
is a higher-level abstraction.

Mark

--------------------------
Mark Guzdial : Georgia Tech : College of Computing : Atlanta, GA 30332-0280
(404) 894-5618 : Fax (404) 894-0673 : guzdial at cc.gatech.edu
http://www.cc.gatech.edu/gvu/people/Faculty/Mark.Guzdial.html