hanging here is usually due to wrong configuration parameters for the driver, so it can't get a connection. In particular your url looks somewhat doubtful.
I really appreciate your reply. You pointed me in right direction. The Atinav driver does require to specify user and password along with url. So by specifying the following snippet in jboss.jcml file solved the problem.
I have found this information at this wonderful site by Suresh, http://personal.vsnl.com/sureshms/jboss.html. This site also describes configuration for other widely used JDBC drivers.
Cheers, long live JBoss..