I want to keep one session, but when I rollback transaction then transaction gets isActive=false, so I can not commit and rollback in next statements by using same transaction. then I need to create new transaction but what is going wrong here ?

        var session = NHibernateHelper.OpenSession();/* It returns new session. */
        var transaction1 = session.BeginTransaction();
        var list1 = session.Query<Make>().ToList(); /* It returs 4 records. */
        session.Delete(list1[2]);

        /* After Rollback, transaction is isActive=false so I can not commit 
         * and rollback from this transaction in future. so I need to create new transaction.
         */
        transaction1.Rollback();

        var transaction2 = session.BeginTransaction();

        /* It returns 3 records. 
         * I am not getting object(which was deleted but after that rollback) here why ? 
         */
        var list2 = session.Query<Make>().ToList(); 

Anyone have idea what is going wrong here ? I am not getting deleted object which was rollback.