HTML5背景音乐的暂停与播放

HTML代码：
    <audio id="myaudio" loop="loop" preload="auto" autoplay="autoplay">
                    <source src="music/纯音乐%20-%20在那遥远的地方%20-%20纯音乐版.mp3" type="audio/ogg" />
                    <source src="music/纯音乐%20-%20在那遥远的地方%20-%20纯音乐版.mp3" type="audio/mp3" />
                </audio>

<img onclick="swap_music()" src="/images/icon_music.png" style="height:30px; vertical-align:middle;" />

JS代码：
 //背景音乐停止与播放
        function swap_music() {
            var oAudio = document.getElementById(‘myaudio‘);
            if (oAudio.paused) {
                oAudio.play();
            }
            else {
                oAudio.pause();
            }
        }