Redirect to a different page when no results are found.

Hello there,

I am working on a site locally and its like a bookstore.The thing i would like to have is, my page results point to a custom url when no results are found.

For example

if i type, on the search form, a book that i don’t have on my site to point to a custom url (like localhost/mybookstore/addyourbook) that will have a form.

Thanks in advance.