In the future please don't PM me with the same content as your post. I check both at the same time, and having to answer both with copy/paste answers merely wastes my time.
With NGUI you don't need to load localization files. Localization.txt places in the Resources folder is loaded automatically, although you can also do it dynamically if you wish. All languages get loaded from the localization file and become available to use. There is no code needed. I suggest giving the user a choice of language selection, not doing it by country... but if you want to just default to a language. Localization.language = "Whatever" will set the active language.