You can use document.onkeypress and if the F5 key is pressed have it call a function that will just refresh your IFRAME.
if you are trying to prevent refreshing of everything except the iframe, you will also have to check for someone press CTRL + R
================================================== =========
I will only tell you how to do it, not do it for you.
Unless, of course, you want to hire me to do work for you.
================================================== =========
http://www.catb.org/~esr/faqs/smart-questions.html
^^Took that from planoie's profile
================================================== =========