Pat, like i said, i am not ajax guru, and Joe will still be the best to help here, but, this may be able to help you in your quest without him.
check that out. sounds similar to what you want, but, you want to do it without clicking anything, so, just incorporate a JS refresh after so many seconds or something. that should work, but, not 100% and dont have time to fool with it myself since i am at work right now. if i get a chance later, i will see if i can put something together if you dont get it yourself.