public ActionResult Configure(ConfigurationModel model)
        {
            if (!ModelState.IsValid)
                return Configure();

            //save settings
            _samplePluginSettings.Greeting = model.Greeting;
            _samplePluginSettings.WidgetZone = model.ZoneId;
            _settingService.SaveSetting(_samplePluginSettings);

            return Configure();
        }
        public ActionResult Configure()
        {
            var model = new ConfigurationModel();
            model.Greeting = _samplePluginSettings.Greeting;

            model.ZoneId = _samplePluginSettings.WidgetZone;
            model.AvailableZones.Add(new SelectListItem() { Text = "Before left side column", Value = "left_side_column_before" });
            model.AvailableZones.Add(new SelectListItem() { Text = "After left side column", Value = "left_side_column_after" });
            model.AvailableZones.Add(new SelectListItem() { Text = "Before right side column", Value = "right_side_column_before" });
            model.AvailableZones.Add(new SelectListItem() { Text = "After right side column", Value = "right_side_column_after" });

            return View("Nop.Plugin.Widgets.SamplePlugin.Views.WidgetsSamplePlugin.Configure", model);
        }