.duration mp3 id3 property

programming flash
1

hello,
I’m having trouble with this:


function playMusicFunc(whichSong) {

	mySound = new Sound();
	curPlaybackPos = 0;
	
	disablePlay();
	song = filePath[whichSong];
	
	mySound.loadSound(song, true);
	mySound.setVolume(curTrackVolume);
	
	dur_txt.text = mySound.duration;
}

Seems simple enough, but…

dur_txt.text = mySound.duration;

always displays 0, any help would be great.
Thanks