def index
      @banners = Banner.all
  
      respond_to do |format|
        format.html # index.html.erb
        format.json { render :json => @banners }
      end
    end
def index
      @banners = Banner.all
  
      respond_to do |format|
        format.html # index.html.erb
        format.json { render :json => @banners }
      end
    end
GET /banners
 GET /banners.json