thank you for reply
the language i need to add is the arabic language, so my letter would be "ar", as i get from the wiki i can upload my folder into the pbx and then reload the pbx and it will recognize the added language, but as i get from ur reply i should modify a file to add this language to apper in the web interface, which file i should modify to do this, i'm a linux user and i can manage with ssh and vi.
please to correct if there is anything wrong with my idea
thanx in advace