Cron script to poll webpage for data

I need a script that will poll another website every 5 seconds and redirect traffic depending on the results of the polled website. For example: ::script polls website in background and pulls list of links from page [linkpool A]:: [user A] visits [mysitedotcom/linkname] and is redirected to a random link from [linkpool A] ::script polls website in background. the page has changed so the script pulls a new pool of links [linkpool B]:: [user B] visits [mysitedotcom/linkname] and is redirected to a random link from [linkpool B] That's the basics of how I'd need the script to work. If anybody has already completed a project similar to this and can provide solution quickly, please bid.