btw thanks inaki for your explanation
but to make things much clear putting my configuration file doesn't mean to have a spoon-feed solution , i mentioned that am still new and before poting my question i searched alot and read much more about avp module either on kamailio site or voice-system tutorial but as am still in my first steps got some diffculty to understand these issues
and finally i put my question for all people not for particular person and who could help me i'd appreciate that