HTML5 Video Volume

I'm currently working on an HTML5 video player, I have it working fully everywhere, except on the iPad. Basically, I can control everything, except the sound, I have a mute button, it works fine on Google Chrome, Firefox 3.6 and Safari on Mac OS, but on the iPad no matter what value I put in video.volume, there is no change happening.

Did anybody get it working properly?

Here's my HTML code:

<video src="video_url" width="608" height="476" autobuffer="autobuffer" id="html5-player" preload>
   Your browser doesn't support HTML5.
</video

And here's the Javascript:

var muted = false;
$j('.player-mute').click(function(){
    if(muted) {
        videoPlayer.volume = 1;
        muted = false;
    } else {
        videoPlayer.volume = 0;
        muted = true;
    }
});