Problème avec EJB 3

bonjour
J'ai un problème que je comprends pas d'ou ça vien?
code d'erreur:

javax.naming.NoInitialContextException: Need to specify class name in environment or system property, or as an applet parameter, or in an application resource file: java.naming.factory.initial
at javax.naming.spi.NamingManager.getInitialContext(NamingManager.java:662)
at javax.naming.InitialContext.getDefaultInitCtx(InitialContext.java:307)
at javax.naming.InitialContext.getURLOrDefaultInitCtx(InitialContext.java:344)
at javax.naming.InitialContext.lookup(InitialContext.java:411)
at client.testEJB.main(testEJB.java:23)

voila le code de l'application:
package sessionBeans;

import javax.ejb.Remote;
@Remote
public interface GestionContactRemote {
public String coucouContact(String nomContact);
}

limplementation:
package sessionBeans;

import javax.ejb.Remote;
import javax.ejb.Stateless;


@Stateless(name ="GestionContactRemote")

public class GestionContactBean implements GestionContactRemote {
public String coucouContact(String nomContact) {
return "Coucou, "+nomContact;
}
}

le client :projet java normal
package client;

import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;

import sessionBeans.GestionContactRemote;

public class testEJB{

public static void main(String[] args) {
try {


Context context = new InitialContext();

GestionContactRemote beanRemote = (GestionContactRemote)context.lookup("GestionContactRemote/remote");


System.out.println(beanRemote.coucouContact("ClientPremierEJB3"));
} catch (NamingException e) {
e.printStackTrace();
}
}
}


merci;