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