Error On relative_url_root

I'm attempting to mash together Adva CMS' Fckeditor and the Fckeditor
plugin provided by Scott Rutherford.

http://blog.caronsoftware.com/2008/6/21/fckeditor-plugin-0-5-1-released

The Scott's plugin has a controller than handles the Fckeditor file
upload and browse, but it errors out on the following lines.

   def upload_directory_path      uploaded = request.relative_url_root.to_s+"#{UPLOADED}/ #{params[:Type]}"      "#{uploaded}#{params[:CurrentFolder]}"    end

If I remove the request.relative_url_root.to_s it works fine.

   def upload_directory_path      uploaded = "#{UPLOADED}/#{params[:Type]}"      "#{uploaded}#{params[:CurrentFolder]}"    end

How do I make this go away without editing the plugin code? I found an
article that says I'm supposed to set it in enviroment.rb but then I
get errors that constants are not defined/found.

http://www.hostingrails.com/37/ActionController-AbstractRequestrelative_url_root

Alan Gutierrez