Eclipse com JPA

javax.persistence.PersistenceException: No Persistence provider for EntityManager named pu1

at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:55)

at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:33)

at br.com.jpa.persistence.BaseDAO.(BaseDAO.java:15)

at br.com.jpa.client.Negocio.main(Negocio.java:15)

package br.com.jpa.client;

import br.com.jpa.model.Cliente;
import br.com.jpa.persistence.BaseDAO;

public class Negocio {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		
		try{					
			BaseDAO<Cliente> dao = new BaseDAO<Cliente>();
					
			//instancio meus objetos na classe cliente
			Cliente cli = new Cliente();
			cli.setNome("Everton");
			cli.setTelefone("7777-8888");
			cli.setCelular("8888-9999");
			cli.setComercial("7777-7777");
			cli.setCep("10100-112");
			cli.setEndereco("Rua do ton");
			cli.setNumero(777);
			cli.setComplemento("nenhum");
			
			//persisto meu objeto no banco de dados
			dao.create(cli);
	
			}catch(Exception ex){
				ex.printStackTrace();
			}
			
	}

}

package br.com.jpa.persistence;

import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.EntityTransaction;
import javax.persistence.Persistence;



public class BaseDAO<T> {

	private static EntityManagerFactory emf;
	private EntityManager em;
	private EntityTransaction tx;

	public BaseDAO() {
		System.out.println("aki\n");
		emf = Persistence.createEntityManagerFactory("pu1");		
		em = emf.createEntityManager();		
		tx = em.getTransaction();	
	}

	public boolean create(T obj) {			
		em.getTransaction();		
		try {			
			tx.begin();
			em.persist(obj);
			em.getTransaction();
			tx.commit();
			em.close();
			return true;
		} catch (Exception e) {
			e.printStackTrace();
			em.getTransaction().rollback();
			return false;
		}
	}
}