We are doing migration of ejb2.1 based applications from jboss 4.3.ga to jboss 7.1.3.Final

In our code, we use something like below. So for Jboss 7.1.3 , how and where to perform this JTS configuration and what will be the NameSpace for this ?

Code snippets:

import javax.transaction.UserTransaction;

// We want to encompass any EJB calls in a single transaction...

            userTran= (UserTransaction)JNDICache.lookup( JTS_JNDI_NAME );

            userTran.begin();