anchor.diff:  
       procedure DoSetMapLevelIndex(ANewIndex: Integer);
   
  -    procedure DoMapLevelWheelScroll(Shift: TShiftState; WheelDelta: Integer);
  +    procedure DoMapLevelWheelScroll(WheelDelta: Integer);
   
       procedure DoMapViewWheelScroll(sb: TScrollBar;Shift: TShiftState; WheelDelta: Integer;MousePos: TPoint);
   
  
positive.code:   end
    else if ss = [ssCtrl] then
    begin
      DoMapLevelWheelScroll(Shift, WheelDelta);
      Handled := True;
    end
    else
  
negative.code:   InvalidateMapContent;
  end;
  
  procedure TfMain.DoMapLevelWheelScroll(WheelDelta: Integer);
  var
    direction : Integer;
  
  