In Dreamweaver you can swap images on a mouseover event using behaviors.

Instead of swapping images, I want to swap flash movies.

Example:

Build a table
place and play a flash movie in a cell
on a mouseover, replace that flash movie with another flash movie.

Can it be done? It apparently can't be done directly - Dreamweaver won't see flash files as swappable. Perhaps there's a workaround.