Hi Sowmya,
What kind of Proxy error you encounterred. Have you ever maintained table HTTPURLLOC？You can check following link regarding this table.
http://wiki.scn.sap.com/wiki/display/BSP/Using+Proxies?original_fqdn=wiki.sdn.sap.com
http://wiki.scn.sap.com/wiki/x/6Qs
Best Regards，
Bruce
