I don't know how to make it, but I know how to use it. LOL I usually use this http://searchenginegenie.com Code (markup):
check this out, pal. http://www.expertcore.org/viewtopic.php?f=67&t=1483 Code (markup): that code is in PHP language.
For what purpose do you need it? (Nothing specific..) Just need to know if has to be automated, or can be manual. Do you just want the PR#, or to verify it is valid.