Better Index method for add books

I will update the github to reflect this

public ActionResult Index([Bind(Include = "Title, ISBN, AuthorName")]NewBook nb)
        {
            Author a = new Author();
            a.AuthorName = nb.AuthorName;
            db.Authors.Add(a);
            db.SaveChanges();
            // for donation get userkey from the session
            Book b = new Book();
            b.BookTitle = nb.Title;
            b.BookISBN = nb.ISBN;
            b.BookEntryDate = DateTime.Now;
            Author author = db.Authors.FirstOrDefault
                (x => x.AuthorName == nb.AuthorName);
            b.Authors.Add(author);

            db.Books.Add(b);
            db.SaveChanges();

            Message m = new Message();
            m.MessageText="Thank you, the book has been added";

            return View("Result", m);
        }