It appears that form_tag :action => 'show_results' is not the same as form_tag 'show_results' . Always use form_tag :action => 'show_results' . Also, when you get strange errors from RJS that ActiveScaffold hide method does not exists, you may need to download the latest version of ActiveScaffold and make sure that the Public folder (where the javascript files are stored) and the Vendor folder (where the plugin is stored) gets updated with that new version.
A blog about real-world software engineering and development problems and solutions.