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