Global.getLanguages ()
construct an array containing languages keys used for retrieving a localized message

Sourcecode in Global/objectFunctions.js:
1:   function getLanguages() {
2:      var languages = new Array("en");
3:      var syslang;
4:      if ((syslang = root.getLocale().getLanguage()) != "en")
5:         languages.unshift(syslang);
6:      if (res.handlers.site) {
7:         var lang = res.handlers.site.getLocale().getLanguage();
8:         if (lang != "en" && lang != syslang)
9:            languages.unshift(lang);
10:     }
11:     return languages;
12:  }