No Persistence provider for EntityManager named
After <persistence-unit name="agisdb">, define the persistence provider name:
<provider>org.hibernate.ejb.HibernatePersistence</provider>
Put the "hibernate-entitymanager.jar" in the classpath of application.
For newer versions, you should use "hibernate-core.jar" instead of the deprecated hibernate-entitymanager
If you are running through some IDE, like Eclipse: Project Properties -> Java Build Path -> Libraries.
Otherwise put it in the /lib of your application.
Make sure that the persistence.xml file is in the directory: <webroot>/WEB-INF/classes/META-INF