Gajanan,
The Bean managed Transaction is only possible in a Session bean. Now to get a real good example you will need to download the J2EE reference implementation 1.2 or 1.3.
These contain sample example code which you can try and work on.
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Mahindrakar
IBM Application Server & Developer Forum Moderator Consultant -
Zensar Technologies ,Pune India.
SCJP2, SCJD2 & SCJEA (Part I)