thanks for you quick reply. I was able to run my application with Hibernate. I used Netbeans for developing J2EE applications and it seems that is a liitle bit complicated to setup a right environment for using Hibernate Entitymanager in Netbeans. Therefore, I created new Hibernate library modules that includes all required jars. See:
http://blogs.sun.com/roller/page/pblaha ... r_netbeans
User can simple install this module and then very easy use persistence and other Hibernate stuff in NetBeans 5.5.