Could you clarify what you're trying to do please?

It looks like you want to retrieve the ISFDB's page for a particular title in the same way as you have done for the name?

Using a GET rather than a POST, you could use the links as displayed on the John Grisham page you show as an example.

So on that page the first Novel "A Time to Kill (1989)" has a link to http://www.isfdb.org/cgi-bin/title.cgi?183131
and going to that link displays the page for that title.

What extra functionality do you need over that - are you trying to search by the text name rather than the ID number?