Java EE (Java Enterprise Edition) General Discussion

hi all
I've simple question on EJB (i'm newbie in EJB)

i wrote some entity and session beans and deployed them on remote computer
server - Sun Application Server.

Question :

I need InitialContext Properties For Client to connect the server.

InitialContext ctx = new InitialContext();
            UserManager bean = (UserManager) ctx
                    .lookup("UserManagerBean/remote");

This does not working. It throws an Exception like this :

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:645)
        at javax.naming.InitialContext.getDefaultInitCtx(InitialContext.java:247)
        at javax.naming.InitialContext.getURLOrDefaultInitCtx(InitialContext.java:284)
        at javax.naming.InitialContext.lookup(InitialContext.java:351)

can anybody help me ?

thx :)