struggling with a frame reload

I have been struggling with some php code to get a frame
to reload. Let's just say I have 2 frames A & B, when I reach
a section of code in frame B (php script) I would like for it to
reload/refresh frame A.

I have scoured the net w/google, found a few links/tips,
but nothing is working. BTW, I am using Mozilla (if that matters).

Any snippets of code would be appreciated

v/r
-Mike