function checkSearch(form)
{
    if(form.q.value == ""){
        alert("本の名前を入力してください");
        form.q.focus();
        return false;
    }
}

function checkIsbn(form)
{
    if(form.book_id.value == ""){
        alert("ISBNを入力してください");
        form.book_id.focus();
        return false;
    }
    url = "/book/" + form.book_id.value;
    location.href = url;
    return false;
}