public int MaxGroupEntityCount(Type entity, string propName, object value, string groupfield)
        {
            ISession currentSession = NHibernateSession.Current;
            var criteria = currentSession.CreateCriteria(entity)
                        .Add(Expression.Eq(propName, value))
                        .SetProjection(Projections.GroupProperty(groupfield))
                        .SetProjection(Projections.Max(groupfield));
                 var gg = criteria.List();
            return criteria.UniqueResult<int>();


        }