var lastID = null;

function playPause(ID) {
	var newID = ID;
	var newAudio = document.getElementById(newID).getElementsByTagName('audio')[0];
	var newAnchor = document.getElementById(newID).getElementsByTagName('a')[0];
	
	if (lastID != null) {
		var lastAudio = document.getElementById(lastID).getElementsByTagName('audio')[0];
		var lastAnchor = document.getElementById(lastID).getElementsByTagName('a')[0];
		
		lastAudio.pause();
		lastAnchor.style.backgroundImage='url(./c/img/btn_play.gif)';
		
		if (lastID==newID) {
			lastID = null;
		} else {
			lastID = newID;
			newAudio.play();
			newAnchor.style.backgroundImage='url(./c/img/btn_pause.gif)';
		}
	} else {
		lastID = newID;
		newAudio.play();
		newAnchor.style.backgroundImage='url(./c/img/btn_pause.gif)';
	}
}

function end(endID) {
	lastID = null;
	var stopAnchor = document.getElementById(endID).getElementsByTagName('a')[0];
	stopAnchor.style.backgroundImage='url(./c/img/btn_play.gif)';
}