This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
Depending on the application server you are using (looks like JBoss), you will have to use the admin interface which shows the JNDI view of the server. (In JBoss you can use the jmx-console's JNDIView MBean). You can then check the jndi tree to find out the jndi name of your EJB and use that jndi name for the lookup. For JBoss see this