Thanks Luli …
I have solved the problem ,although I am using Mysql as the DB and not Oracle .
I made the changes in the Alfresco war file which I then deployed on JBoss .
Now here I would like to mention that earliar I was using MySql version 5.0 which could have been the cause of the problem.
When I changed the DB to MySQL version 5.1 and made the required changes in the alfresco war file ,and it was up and running .
I now need to deploy alfresco as a portlet ,for which I believe I would need to incorporate the portlet.xml,*-object.xml and jboss-instance.xml files into the war file .
Is there any custom portlet (JBoss) that can retrieve content from the alfresco repository ????
Regards
Venky