procedure TMyDrawGrid.GridMouseWheel(shift: TShiftState; Delta: Integer);
begin
if WheelBrakes > 0 then begin
if fWheelDelta <> Delta then begin
fWheelDelta := delta;
fWheelCount := 0;
end;
inc(fWheelCount);
if fWheelCount <= fWheelBrakes then exit;
fWheelCount := 0;
end;
inherited GridMouseWheel(shift, Delta);
end;