def hash_to_params(hash)
  hash.keys.inject("") do |qs, key|
    qs << "&" unless qs.blank?
    qs << if Array === hash[key]
            k = CGI.escape(key.to_s)
            hash[key].map { |value| "#{k}=" << CGI.escape(value.to_s) }.join("&")
          else
            CGI.escape(key.to_s) << "=" << CGI.escape(hash[key].to_s)
          end
  end
end