[Страдалецъ]

Код:

 for i := 0 to DBGrid1.SelectedRows.Count - 1
 do begin
    DBGrid1.DataSource.DataSet.Bookmark := DBGrid1.SelectedRows[i];
    DBGrid1.DataSource.DataSet.Edit;
    DBGrid1.DataSource.DataSet.Fields[3].AsString := 'Отпущено';
    DBGrid1.DataSource.DataSet.Post;
    end;