# File app/controllers/application.rb, line 124
  def sort_for_fields(sortable)
    key = [:controller, :action].map {|k| request.path_parameters[k]}.join('/')
    session[key] ||= {}

    if params[:sort_by] and sortable.include? params[:sort_by].to_s
      session[key][:sort_by] = params[:sort_by]
    end
    session[key][:sort_by] ||= sortable[0]

    session[key][:sort_by]
  end