NHibernate 中Between的使用方法

     public virtual ArrayList QueryEmployeeDemissionSettlementListByExec(DateTime begin,DateTime end)
        {
            using (ISession session = OpenSession())
            {
                return (ArrayList)session.CreateCriteria(typeof(EmployeeDemissionInfo)).Add(Expression.Eq("SettlementStatus", ExecuteStatus.Executed)).Add(Expression.Between("SettlementDate", begin, end)).List();
            }
        }