Script Summary: Search the San Francisco Public Library Catalog from Amazon book listings.
This checks the ISBN number from an Amazon book listing against the San Francisco Public Library's listing. If there's a match, the script inserts a link on the Amazon page to the corresponding entry at the library.
This has less functionnality than the original script, which checked the library page for the words Check Shelf, which indicated the book was available. That stopped working, but I'm happy to update the script is some fine soul wants to grab the code from the library lookup plugin and make it work with this one.
