# File lib/www/mechanize/util.rb, line 60
        def detect_charset(src)
          tmp = NKF.guess(src || "<html></html>")
          if RUBY_VERSION >= "1.9.0"
            enc = tmp.to_s.upcase
          else
            enc = NKF.constants.find{|c|
              NKF.const_get(c) == tmp
            }
            enc = CODE_DIC[enc.intern]
          end
          enc || "ISO-8859-1"
        end