How to control Flash Player playback using JavaScript?

Question

I have a local file-based web page (HTML file) containing an embedded YouTube video.
Now I want to write some JavaScript to control the Player's playback parameters, like volume, mute, play, stop etc., using JavaScript in the file. However, I don't seem to be able to access any of these function.
Can someone please enlighten me on what I need to do to be able to control Flash Player from JavaScript?

Answer 1

I'm not acquainted with Flash too much, I'm afraid... Both paged didn't give any example I could leverage.
I'm searching for something equivalent to something like this:
document.getElementById("MyMoviePlayer").mute();