Hi Prathibha,
Wish you very happy new year
pls refer this links
http://scn.sap.com/thread/1801606
http://www.sap-press.de/download/dateien/2724/sappress_100_things_authorizations_in_sap.pdf
http://help.sap.com/saphelp_nw04/helpdata/en/52/671285439b11d1896f0000e8322d00/content.htm
Regards
Nayeem