EJB3.0 Error

I am trying to understand what this error is telling me when I deploy my EJB jar to the application server.

Field javax.persistence.EntityManager com.russ.library.BookBean.em @PersistenceUnit in error: EMPTY STRING unitName but there is no deployments in scope

Any help would be greatly appreciated.

Russ

[330 byte] By [supercoder97a] at [2007-10-2 16:35:43]