gistfile1.cs

        public void SavingFile()
        {
            StreamWriter writer = new StreamWriter("books.txt");

            foreach (Book book in books)
            {
                writer.WriteLine(book.ToString());

            }
        }

        public void LoadingFile()
        {
            const char DELIM = '\t';
            string recordIn = "";
            string part;

            FileStream file = new FileStream("books.txt", FileMode.Open, FileAccess.Read);
            StreamReader reader = new StreamReader(file);

            while (reader.Peek() != -1)
            {

                recordIn = reader.ReadLine();
                part = recordIn.Split(DELIM);

                part[0] = ISBN Isbn(part[0]);
                part[1] = book.LastName[1];
                part[2] = book.FirstName;
                part[3] = book.Title;
                part[4] = book.Year;
                part[5] = book.Price;
            }

            if (book.Valid() && book.Normalize())
	{
		 book.Add(books.txt)
	}

            reader.Close();
            file.Close();
        }