Cannot use EJB inside ManagedBean

Question

I have created an Enterprise Project with Netbeans, so there is a project for the EJB's and a project for the web components. I have this code for the EJB:

@Stateless
public class JosContentFacade extends AbstractFacade<JosContent> {

@PersistenceContext(unitName = "com.guiatic_GuiaTIC-ejb_ejb_1.0-SNAPSHOTPU")
private EntityManager em;

@Override
protected EntityManager getEntityManager() {
    return em;
}

public JosContentFacade() {
    super(JosContent.class);
}

}

and this code for the ManagedBean:

@Named(value = "showRelateds")
@RequestScoped
public class showRelateds {

@EJB
private JosContentFacade josContentFacade;

private String msg;

/**
 * Creates a new instance of showRelateds
 */
public showRelateds() {
}

public String getMsg() {
    msg = "MENSAJE DE PRUEBAS 3!!!";
    return msg;
}

public void setMsg(String msg) {
    this.msg = msg;
}

}

If I remove this line:

@EJB
private JosContentFacade josContentFacade;

The bean works properly, but with such line, it doesn't show me any error, but the bean doesn't work.