JPAContainerFactory error

Hi,
My environment:
Windows 8, Vaadin 7.1.7, JPAContainer 3.1, PostgreSQL 9.2, EclipseLink 2.5 (JPA 2.1)

In my persistence, I have configured:


org.eclipse.persistence.jpa.PersistenceProvider

My code snippet is as follows:
private static EntityManager em = JPAContainerFactory
.createEntityManagerForPersistenceUnit(“mydb4data”); // mydb4data being my database in postgresql server

The following exception is occuring:
Caused by: javax.persistence.PersistenceException: No Persistence provider for EntityManager named mydb4data
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:85)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:54)
at com.vaadin.addon.jpacontainer.JPAContainerFactory.createEntityManagerForPersistenceUnit(JPAContainerFactory.java:122)

Has anyone come across a similar situation or any hint or pointer might help.

Rgds
Mi