Can't get ProfileService Jboss AS 5.1 GA

I'm trying to get ProfileService using the following:

Context ctx = server.getNamingContext();
contextInst.set(ctx);
profileService = (ProfileService) ctx.lookup("ProfileService");
But got the following error:

javax.naming.NameNotFoundException: ProfileService not bound

I'm using JBoss AS 5.1 GA, in web profile.