No Persistence provider for EntityManager named …

I have my persistence.xml with the same name, using toplink, under META-INF directory. Then I have my code calling it with...

EntityManagerFactory factory =Persistence.createEntityManagerFactory("openjpa");

Yet, I got the following error message

2010-08-19 09:22:41,018 [main] ERROR - No Persistence provider for EntityManager named openjpa
javax.persistence.PersistenceException: No Persistence provider for EntityManager named openjpa
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:89)
    at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:60)

Here is the persistence.xml...

<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence"
   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd"
   version="1.0">
   <persistence-unit name="openjpa" transaction-type="RESOURCE_LOCAL">
   <jta-data-source>java:/DefaultDS</jta-data-source>
      <properties>
         <property name="hibernate.dialect" value="org.hibernate.dialect.MySQL5Dialect"/>
         <property name="hibernate.hbm2ddl.auto" value="update"/>
         <property name="hibernate.connection.driver_class" value="org.gjt.mm.mysql.Driver"/>
         <property name="hibernate.connection.username" value="root"/>
         <property name="hibernate.connection.password" value=""/>
         <property name="hibernate.connection.url" value="jdbc:mysql://localhost:3306/bookshop?useCode=true&amp;characterEncoding=UTF-8"/>
      </properties>
   </persistence-unit>
</persistence>

It should have been in the classpath... Yet, I got the above error... Really appreciate any help... Thanks