Passing Parameters Between Websites

I need to pass a parameter from Google Adwords to my website, then if the user performs the desired action, pass it to a 3rd site (not mine), which will grab it and store it for me to look at later. So here's what arrives at my site: [login to view URL] (this is the search term the user to find my Adwords ad) When they arrive on the landing page, the user has the option to click on several links to request more information, or they could wander off to another part of the website altogether (or leave). But if they do take action before leaving the site, the search term needs to be available to be passed to the 3rd site as AFF=brackets_word_clicked_upon It's possible for someone to arrive at the page without having come through Adwords, and the link to the action page needs to work regardless of how the visitor found the site. So the existence of the variable needs to be checked and passed along if it exists as AFF=brackets_word_clicked_upon I've found various posts talking about using Javascript to parse the URL and somehow passing the results along, but nothing that tells me the exact syntax for doing this. I've also seen some suggestions for setting a cookie, but again, nothing that tells me exactly what to do every step of the way. I have done a little programming so I do (somewhat) understand the concept of passing parameters, but what I really need are step by step instructions on what code to place where, and then what, etc. ## Deliverables 1) Complete and fully-functional working program(s) in executable form as well as complete source code of all work done. 2) Deliverables must be in ready-to-run condition, as follows (depending on the nature of the deliverables): a) For web sites or other server-side deliverables intended to only ever exist in one place in the Buyer's environment--Deliverables must be installed by the Seller in ready-to-run condition in the Buyer's environment. b) For all others including desktop software or software the buyer intends to distribute: A software installation package that will install the software in ready-to-run condition on the platform(s) specified in this bid request. 3) All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site per the coder's Seller Legal Agreement). ## Platform WWW, any browser