How to associate a new document with a specific language?

Hi all, I asked before whether it is possible to change the language of document by the API. If my understanding is well, the XWiki has a default language. So when a new document is created the default language is associated to it. I tried to exploit the "XWikiContext" to modify the lanaguage but without success. (Thanks to all people for the explanation of different use of the "Context") How it is possible to associate with a new document a specific language? Any help will be deeply appreciated, thanks in advance. Best wishes ---------------------------------- Youcef Bey