I created a simple SesionBean. I deployed into the JBoss 4.0.5 and when i try to access the bean i get the following error:

Exception in thread "main" javax.naming.NoInitialContextException: Cannot instan
tiate class: org.jnp.interfaces.NamingContextFactory [Root exception is java.lang.ClassNotFoundException: org.jnp.interfaces.NamingContextFactory]
at javax.naming.spi.NamingManager.getInitialContext(NamingManager.java:6
57)
at javax.naming.InitialContext.getDefaultInitCtx(InitialContext.java:247
)
at javax.naming.InitialContext.init(InitialContext.java:223)
at javax.naming.InitialContext.(InitialContext.java:175)
at client.SimpleSessionClient.main(SimpleSessionClient.java:9)
Caused by: java.lang.ClassNotFoundException: org.jnp.interfaces.NamingContextFac
tory
at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:268)
at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:242)
at com.sun.naming.internal.VersionHelper12.loadClass(VersionHelper12.jav
a:42)
at javax.naming.spi.NamingManager.getInitialContext(NamingManager.java:6
54)
... 4 more

Please give me some help about this.