Sync two flash banners in AS2?

I was wondering of any methods to sync two flash banners? What I mean is that when the page loads neither banner starts until both are ready?

I will have two flash banner like this:

|Banner 1|
(something else between them, html css)
|Banner 2|

Both banners will contain video, that needs to be played in sync.

Any ideas? I would prefer AS2, because the site I will run these two banners on prefers AS2.

I read something about LocalConnection in AS3, anything similiar in AS2? And does it work on all OS / browsers? Can it be done with Javascript?