I been trying to solve this problem for a couple of days now and no luck!
a little help would be appreciated. THanks
I am getting this Exception every time I run my client.

This is my main class

 public static void main(String[] args) {

 KBClient c = new KBClient();
 ClassificationRemote r = c.lookupNewClassificationBean();
 //Setting and Adding project
 KnowledgeBase first = new KnowledgeBase();
 Project p = new Project(8);
 p.setProjectName("Test Project");
 p.setDescription("testing");
 first.setKnowledgeID(200);
 first.setKnowledgeName("Demo");
 first.setKnowledgeCategory("Classification");
 first.setProjectID(p);
 r.addProject(p);
 r.addKnowledgeBase(first);
 }

 private ClassificationRemote lookupNewClassificationBean() {
 try {
 Hashtable props = new Hashtable();
 props.put("java.naming.factory.initial", "org.jnp.interfaces.NamingContextFactory");
 props.put("java.naming.factory.url.pkgs", "org.jboss.naming:org.jnp.interfaces");
 props.put("java.naming.provider.url", "localhost");
 Context c = new InitialContext(props);
 return (ClassificationRemote) c.lookup("ClassificationBeanFinal/remote");
 }
 catch(NamingException ne) {
 System.out.println("here!");
 Logger.getLogger(getClass().getName()).log(Level.SEVERE,"exception caught" ,ne);
 throw new RuntimeException(ne);
 }
 }

public void addKnowledgeBase(KnowledgeBase kb){
 KnowledgeBase temp = em.find(KnowledgeBase.class, kb.getKnowledgeID());
 if(temp == null){
 em.persist(kb);
 em.flush();
 }
 }

Exception in thread "main" javax.ejb.EJBException: javax.persistence.PersistenceException: org.hibernate.PersistentObjectException: detached entity passed to persist: EntityBean.Project
 at org.jboss.ejb3.tx.Ejb3TxPolicy.handleExceptionInOurTx(Ejb3TxPolicy.java:63)
 at org.jboss.aspects.tx.TxPolicy.invokeInOurTx(TxPolicy.java:83)
 at org.jboss.aspects.tx.TxInterceptor$Required.invoke(TxInterceptor.java:191)
 at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
 at org.jboss.aspects.tx.TxPropagationInterceptor.invoke(TxPropagationInterceptor.java:76)
 at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
 at org.jboss.ejb3.stateless.StatelessInstanceInterceptor.invoke(StatelessInstanceInterceptor.java:62)
 at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
 at org.jboss.aspects.security.AuthenticationInterceptor.invoke(AuthenticationInterceptor.java:77)
 at org.jboss.ejb3.security.Ejb3AuthenticationInterceptor.invoke(Ejb3AuthenticationInterceptor.java:106)
 at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
 at org.jboss.ejb3.ENCPropagationInterceptor.invoke(ENCPropagationInterceptor.java:46)
 at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
 at org.jboss.ejb3.asynchronous.AsynchronousInterceptor.invoke(AsynchronousInterceptor.java:106)
 at org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:101)
 at org.jboss.ejb3.stateless.StatelessContainer.dynamicInvoke(StatelessContainer.java:278)
 at org.jboss.aop.Dispatcher.invoke(Dispatcher.java:106)
 at org.jboss.aspects.remoting.AOPRemotingInvocationHandler.invoke(AOPRemotingInvocationHandler.java:82)
 at org.jboss.remoting.ServerInvoker.invoke(ServerInvoker.java:734)
 at org.jboss.remoting.transport.socket.ServerThread.processInvocation(ServerThread.java:560)
 at org.jboss.remoting.transport.socket.ServerThread.dorun(ServerThread.java:369)
 at org.jboss.remoting.transport.socket.ServerThread.run(ServerThread.java:165)
Caused by: javax.persistence.PersistenceException: org.hibernate.PersistentObjectException: detached entity passed to persist: EntityBean.Project
 at org.hibernate.ejb.AbstractEntityManagerImpl.throwPersistenceException(AbstractEntityManagerImpl.java:629)
 at org.hibernate.ejb.AbstractEntityManagerImpl.persist(AbstractEntityManagerImpl.java:218)
 at org.jboss.ejb3.entity.TransactionScopedEntityManager.persist(TransactionScopedEntityManager.java:182)