Since it is automatic, you must have to set something in table during design time. Can you suggest some links to for this topic? Is this feature avaible only in Sql...

Try this link:

http://msdn2.microsoft.com/en-us/library/ms170246(SQL.90).aspx (for 2005)

http://msdn.microsoft.com/msdnmag/issues/04/08/SQLServerReportingServices/(for 2000). here is a demo link: http://www.microsoft.com/sql/prodinfo/previousversions/rs/rs_authoringdemo.mspx

hope this helps..

kushpaw