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;

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

            // Read each line
            while (reader.Peek() != -1)
            {

                Book book = new Book();
                // Read this line
                recordIn = reader.ReadLine();
                // Split the line into fields
                part = recordIn.Split(DELIM);

                // Put the information in our book object
                book.Isbn = new ISBN(part[0]);
                book.LastName = part[1];
                book.FirstName = part[2];
                book.Title = part[3];
                book.Year = Convert.ToInt32(part[4]);
                book.Price = Convert.ToDouble(part[5]);

                // if it is valid and it is unique
                if (book.Valid() && NewBook(book))
	        {
                 // Add our book to our books array
		 books.Add(book)
	        }
            }

            // Close our file handles
            reader.Close();
            file.Close();
        }