// Inicializa la pantalla
function Load(isbn) {
    var viewportDiv = document.getElementById("viewport");
    var viewer = new google.books.DefaultViewer(viewportDiv, { 'showLinkChrome': false });
    viewer.load(isbn, handle_not_found);
}

function handle_not_found() {
    var viewportSection = document.getElementById("preview_section");
    alert("No se encontró el producto en Google Books");
    viewportSection.style.display = 'none';
}

google.load("books", "0");