IFRAME Navigation Controls?

[Rogue]

I have a web page I am working on at work which loads several different pages into IFRAMEs. Is there anyway to control each IFRAME window separately from the other. In other words, if I have Amazon.com loaded in one IFRAME and Anandtech.com loaded in another, and I want to go one back back in just the Amazon.com IFRAME, how would I do it and what is the code to make it happen? I have created navigation buttons to click on to navigate the IFRAME, only I don't know how to make them work. Help?