function getFirstBrowserLanguage() {
    var nav = window.navigator,
        browserLanguagePropertyKeys = ['language', 'browserLanguage', 'systemLanguage', 'userLanguage'],
        i,
        language,
        len,
        shortLanguage = null;
    if (Array.isArray(nav.languages)) {
        for (i = 0; i < nav.languages.length; i++) {
            language = nav.languages[i];
            len = language.length;
            if (!shortLanguage && len) {
                shortLanguage = language;
            }
            if (language && len>2) {
                return language;
            }
        }
    }
    for (i = 0; i < browserLanguagePropertyKeys.length; i++) {
        language = nav[browserLanguagePropertyKeys[i]];
        len = language.length;
        if (!shortLanguage && len) {
            shortLanguage = language;
        }
        if (language && len > 2) {
            return language;
        }
    }
    return shortLanguage;
};
carrotquest.identify({'Browser language': getFirstBrowserLanguage()});