switch (...)
            {
               case  1 :
                    CrystalReport1 myReport1 = new CrystalReport1 ();
                    myReport1.SetDataSource(CurrentDataset);
                    ...
               break;
               case  2 :
                    CrystalReport2 myReport2 = new CrystalReport2 ();
                    myReport2.SetDataSource(CurrentDataset);
                    ...
               break;
               ...
            }