# File lib/cgikit/handler.rb, line 188
    def query_string( hash = {} )
      str = ''
      keys = hash.keys.sort do |a, b|
        a.to_s <=> b.to_s
      end
      keys.each do |key|
        value = hash[key]
        if Array === value then
          value.each do |item|
            str << query_association(key, item)
          end
        else
          str << query_association(key, value)
        end
      end
      str.chop!
      str
    end