def title_main_validate(root)
        title_main_en = root.at("//title[@type='title-main' and @language='en']")
        title_main_zh = root.at("//title[@type='title-main' and @language='zh']")
        if title_main_en.nil? && !title_main_zh.nil?
          @log.add("Style", title_main_zh,  "No English Title!")