[Plugin: W3 Total Cache] exception of php function possible? what about iframe?

HI,

I’m trying to make my banner rotator script to work with caching plugin. Obviously w3 total cache caches the function that I use to call banner and it never changes. Is there a way to exclude certein php function from being cached?

If not,

I was thinking to make an iframe, put my function there in ads.php and show it on page through iframe. would this work?