public override bool OnCreateOptionsMenu (Xamarin.ActionbarSherlockBinding.Views.IMenu menu) {
            SupportMenuInflater.Inflate(Resource.Menu.menu_search, menu);
            return base.OnCreateOptionsMenu (menu);
        }

        public override bool OnOptionsItemSelected (Xamarin.ActionbarSherlockBinding.Views.IMenuItem item){
            switch (item.ItemId) {
            case Resource.Id.menu_search:
                //FAI QUALCOSA
                return true;

            default:
                return base.OnOptionsItemSelected (item);
            }
        }