When I ran into that exception it was because my client was missing some jars (for JBoss 3.0). Check your classpath and make sure that all the necessary client jars are there.
Thanks for your reply, but what are the necessary client jars needs to put in classpath,
i have following jars the defaultroot\web-inf\lib\ folder.:jass, jboss-client, jboss-j2ee, bossmq-clinet, jbosssx-client, jnp-clinet, log4j.
do you think they are enough.