Hibernate version: 2.0 beta1

I was waiting for ExecuteUpdate in nhibernate for some time. I was happy that it was finally implemented in version 2.0, it is something wrong with it or I am doing something not the right way.

IQuery q = NHibernateSession.CreateQuery("update Pictures set PublicPicture = :pub where PictureId = :id");

And i get an excepton :
query must begin with SELECT or FROM: update [update `Pictures` set PublicPicture = :pub where PictureId = :id]

How to use new ExecuteUpdate method with hql ?