View.Set ("graphics:max,max")
var size : int := 50
var mx, my, mb : int



loop
   mousewhere (mx, my, mb)
   drawfillbox (mx-size, 0, mx + size, 50, black)
   drawfillbox (mx - size - 1, 0, 0, 50, white)
   drawfillbox (maxx,0, mx+ size + 1, 50, white)
end loop