internationalization of web site

Hi, Sorry to send this email on both mailing lists but as i suppose that both are concerned by it, i did. i would like to make my web site tune to user language. for that i was thinking to create some XML files where all words can be found and based on the icon (country flag) that user clicked, i will load a specific XML file to tune my PHP pages. i know from Java exprience that it exists also another possibility via browser setup for preference in language, but i do not know how it works in PHP. please, could you give me some tips, helps, or tutorial for such request ? thanks a lot, Alain