//tim kiem tag
        public ActionResult TimKiem(string keyword, int?page)
        {
            int pageNumber = (page ?? 1);

            keyword = RejectMarks(keyword);
            IList <TagTinTuc>     danhSachTags = _tagTinTucRepository.TimKiem(keyword.Trim().ToLower());
            TagTinTucModelTimKiem timkiem      = new TagTinTucModelTimKiem()
            {
                DanhSachTags   = danhSachTags.ToPagedList(pageNumber, pageSize),
                soluongtimduoc = danhSachTags.Count()
            };

            ViewData["key"] = keyword;
            return(View(timkiem));
        }