Hi Nahas,

Cisco IP Phone 7961G/7961G-GE and 7941G/7941G-GE

Customizing the Cisco Unified IP Phone

From this doc;

http://www.cisco.com/en/US/products/hw/phones/ps379/products_administration_guide_chapter09186a00805ecd36.html

Cisco Unified IP Phone 7965G and 7945G Administration Guide for Cisco Unified Communications Manager 6.1

Customizing the Cisco Unified IP Phone

http://www.cisco.com/en/US/docs/voice_ip_comm/cuipph/7965g_7945g/6_1/english/administration/guide/7965cst.html

Customizing Cisco IP Communicator

http://www.cisco.com/en/US/docs/voice_ip_comm/cipc/1_1/english/administration/guide/CADcst.html

Also, have a look at this fantastic post from Martin;

http://forum.cisco.com/eforum/servlet/NetProf?page=netprof&forum=Unified%20Communications%20and%20Video&topic=IP%20Telephony&CommCmd=MB%3Fcmd%3Dpass_through%26location%3Doutline%40%5E1%40%40.2cc15c8a/8#selected_message

Hope this helps!

Rob