def post_page(url,post_data='')
      url = URI(url)

      prepare_request(url) do |session,path,headers|
        new_page = Page.new(url,session.post(path,post_data,headers))

        # save any new cookies
        @cookies.from_page(new_page)

        yield new_page if block_given?
        return new_page
      end
    end
def post_page(url,post_data='')
      url = URI(url)

      prepare_request(url) do |session,path,headers|
        new_page = Page.new(url,session.post(path,post_data,headers))

        # save any new cookies
        @cookies.from_page(new_page)

        yield new_page if block_given?
        return new_page
      end
    end
Posts supplied form data and creates a new Page object from a given URL.

 @param [URI::HTTP] url
   The URL to request.

 @param [String] post_data
   Form option data.

 @yield [page]
   If a block is given, it will be passed the page that represents the
   response.

 @yieldparam [Page] page
   The page for the response.

 @return [Page, nil]
   The page for the response, or `nil` if the request failed.

 @since 0.2.2