Afundar linha do DbGrid

procedure TForm1.DBGrid1DrawColumnCell(Sender: TObject; const Rect: TRect;
  DataCol: Integer; Column: TColumn; State: TGridDrawState);
begin
  if DBGrid1.DataSource.DataSet.RecNo = nDuploClique then
    DBGrid1.Canvas.Brush.Color := clRed
  else
    DBGrid1.Canvas.Brush.Color := clWindow;
end;

procedure TForm1.DBGrid1DblClick(Sender: TObject);
begin
  nDuploClique := DBGrid1.DataSource.DataSet.RecNo;
end;