// GET: Search
        public ActionResult Index(int id = -1, String query = "", int page = 1, int pageSize = 4)
        {
            String[]             searchSequence = query.Split(' ');
            IEnumerable <String> wordSequesnce  = searchSequence.ToList();
            List <BOOK>          books          = new List <BOOK>();

            if (id == -1 && query == "")
            {
                books = BookModel.GetBooks();
            }
            else if (id != -1 && query != "")
            {
                IEnumerable <BOOK_CATEGORY> bookCat = BookModel.GetBookCategories();
                foreach (BOOK_CATEGORY bCat in bookCat)
                {
                    if (bCat.CATEGORYID == id && bCat.BOOK.NAME.ToLower().Contains(query.ToLower()) || bCat.BOOK.SYNOPOSIS.ToLower().Contains(query.ToLower()))
                    {
                        books.Add(bCat.BOOK);
                    }
                }
            }
            else if (id == -1 && query != "")
            {
                IEnumerable <BOOK> listBooks = BookModel.GetBooks();
                foreach (BOOK book in listBooks)
                {
                    if (book.NAME.ToLower().Contains(query.ToLower()) || book.SYNOPOSIS.ToLower().Contains(query.ToLower()))
                    {
                        books.Add(book);
                    }
                }
            }
            else if (id != -1 && query == "")
            {
                IEnumerable <BOOK_CATEGORY> bookCat = BookModel.GetBookCategories();
                foreach (BOOK_CATEGORY bCat in bookCat)
                {
                    if (bCat.CATEGORYID == id)
                    {
                        books.Add(bCat.BOOK);
                    }
                }
            }
            IPagedList <BOOK> pBooks = new PagedList <BOOK>(books, page, pageSize);

            return(View(pBooks));
        }