Thread:Project:Support desk/my interface language

hi thank u 4 this mediawiki my version is 1.16wmf4 (r76812) my quastion is : can i make the defualt interface language for my mediawiki site arabic ? that meaning : if user (with no acount) visit my mediawiki site he get it with arabic interface not with inglish. can i get it with arabic fully ?? thank u very mutch