极度简单的代码，就是不能运行，求大神阅一下！
<html> <head>
<title>Audio</title>
<script>
function playSound(src){
var _s = document.getElementById('snd');
if(src!='' && typeof src!=undefined){
_s.src = src;
}
}
</script>
</head>
<body>
<input id="snd" type="button" value="play" onclick="playSound('http://mp3.')">
</body>
</html>
