Browser auto refreshing .XML file?

I have a flash movie in my site that is loading external images fed through an external .xml file. Everything works fine except for the fact that in order for the site to display the most recent images that I have uploaded and modified in the .xml file I have to reset the cache in my web browser. Is there anyway to modify the .xml file so that it will expire and not be saved in the browser’s cache or another way to modify the actionscript to always call the most recent .xml file???