Trying to use constructor function to update the object classes of a book using a button click. I keep getting errors saying that the 3 variables (`book1`, `book2`, and `book3`) cannot be found.

Not sure as to why, but I believe its a very simple error (or maybe a very drastic one). I want the info to be displayed in an alert, but can I use `document.getElementById().innerHTML = ;` to update a `<p></p>`?

```html
<!DOCTYPE html>
<html>
<head>
    <title>JavaScript Book Object</title>
</head>
<body>
    <h1>Two Examples of Books</h1>
    <h3>Read Available Books</h3>
    <input type = 'button' value = 'To Kill a Mockingbird' onclick = 'book1.read();'/>
    <input type = 'button' value = 'The Outsiders' onclick = 'book2.read();'/>

    <h3>Read in your own custom book</h3>

    <input type = 'button' value = 'Enter your book' onclick = 'book3.promptNewBookInfo();'/>
    <input type = 'button' value = 'Your Book' onclick = 'book3.read();'/>

    <script type = "text/javascript">
        var book1 = new Book("To Kill a Mockingbird", "Harper Lee", "David Johnson", 281, "Social Drama");
        var book2 = new Book("The Outsiders", "S. E. Hinton", "(none)", 192, "Young Adult Fiction");
        var book3 = new Book("tbd", "tbd", "tbd", 0, "tbd");

        function Book(ti, au, ill, pgs, gnr) {
            this.title = ti;
            this.author = au;
            this.illustrator = ill;
            this.pages = pgs;
            this.genre = gnr;

            this.read = funcion() {
                var newBook = this.title + " by" + this.author + "and illustrated by:" + this.illustrator + " is" + this.pages + " pages long" + "and is " + this.genre;
                alert(newBook);
            };
            this.promptNewBookInfo = function()
            {
                this.title = prompt("What is the title?");
                this.author = prompt("Who is the nook written by?");
                this.illustrator = prompt("Who is the book illustrated by?");
                this.pages = parseInt(prompt("How many pages is the book?"))
                this.genre = prompt("What genre is your book?");
                alert (this.title + "is now ready to be read!");
            }
        }

    </script>
</body>
</html>

```