def query_string(params, prefix = nil) #:nodoc:
      prefix = "#{prefix}." if prefix
      params.keys.sort { |a, b| a.to_s <=> b.to_s }.collect do |key|
        case val = params[key]
          when Hash
          query_string(val, key)
          else
          "#{prefix}#{key}=#{escape val}"
        end
      end.join('&')
    end
def query_string(params, prefix = nil) 
      prefix = "
      params.keys.sort { |a, b| a.to_s <=> b.to_s }.collect do |key|
        case val = params[key]
          when Hash
          query_string(val, key)
          else
          "
        end
      end.join('&')
    end
def query_string ( params , prefix = nil ) #:nodoc: prefix = "#{prefix}." if prefix params . keys . sort { | a , b | a . to_s <=> b . to_s } . collect do | key | case val = params [ key ] when Hash query_string ( val , key ) else "#{prefix}#{key}=#{escape val}" end end . join ( '&' ) end
Flattens a possibly-nested hash into a query string for Amazon.
 With Amazon, nested hashes are flattened with a period, as follows:

   AmazonFlexPay::Util.query_string(:foo => {:hello => 'world'})
   => "foo.hello=world"
Flattens a possibly - nested hash into a query string for Amazon . With Amazon nested hashes are flattened with a period as follows :