audio.test.html

<iframe src="http://alexandre.alapetite.fr/doc-alex/html5-audio/" width="100%" height="100%"></iframe>

<script>
onload = function () {
var audio = document.createElement('audio');
document.body.appendChild(audio);
audio.src="1.mp3";
audio.play();
}

var a = 1.236;
alert(a.toFixed(1))
</script>