function getMediaPlayer(doc) {
	if (! doc)
		doc = document;

	return doc.getElementById('mediaplayer');
}

function doPlay() {
	mp = getMediaPlayer();
	mp.controls.Play();
}

function doStop() {
	doPause();
	return;
	mp = getMediaPlayer();
	mp.controls.Stop();
}

function doPause() {
	mp = getMediaPlayer();
	mp.controls.Pause();
}

 function doFullscreen(){
 	mp = getMediaPlayer();

	if (mp.playState == 3)
 		mp.fullscreen='true';
}

function changeVolume(direction) {

    mp = getMediaPlayer();

    actVolume = mp.settings.volume;
	var wmVolumeStep = 10;
	var wmVolumeMin = 0;
	var wmVolumeMax = 100;

    if (direction == 'up') { newVolume = actVolume + wmVolumeStep; }
    else { newVolume = actVolume - wmVolumeStep; }

    if (newVolume < wmVolumeMin) { newVolume = wmVolumeMin; }
    if (newVolume > wmVolumeMax) { newVolume = wmVolumeMax; }

    mp.settings.volume = newVolume;
}

function changeMute() {
	var mp = getMediaPlayer();

	var isMute = mp.settings.mute;
	var newMute = (! isMute);

	mp.settings.mute = newMute;

    document.mute_off.style.display = (newMute) ? 'none' : 'inline';
    document.mute_on.style.display = (newMute) ? 'inline' : 'none';
}