add multi-lingual function for admin panel

Half completed project, front-end three languages(english, chinese,arabic), but admin panel only can upload english, for another two languages content ,i must go to the xml file to do the translation. we want : 1. admin panel can upload english,chinese,and arabic content in same time by using same database to show the content in front-end. 2. adjust the site front-end style.-----delete one white place up of the menu and one black place up of the menu.