I want to include something in my PDF document so I can record when it gets opened.
I can already do this with Word, Powerpoint, Excel, HTML and Email (see http://www.ReadNotify.com
to see this working) and it works by embedding a link to a 1 pixel transparent image that comes from my CGI server. I can easily see when my file has been given to someone else when I get a new IP address and browser string arrive at my web server.
eg: <img src="http://www.g07cfz5pcfldn0.readnotify.com/ms.asp?g07cfz5pcfldnA&
Is there any way to do this in a PDF file?
Each time I try - it "takes" my graphic from my server and keeps a copy of it (so it never asks again), even though the server includes all the correct HTTP anti-cache headers etc.