我用this.setAttribute('animation-play-state','running');为什么动画不会暂停呢？

window.onload=function(){
	var music=document.getElementById('music').getElementsByTagName('img')[1];
	var audio=document.getElementsByTagName('audio')[0];
	music.onclick=function(){
		if (audio.paused) {
			audio.play();
			//this.style.animationPlayState='running';
			this.setAttribute('animation-play-state','running');
		}else {
			audio.pause();
			//this.style.animationPlayState='paused';
			this.setAttribute('animation-play-state','paused');
		}
	}
}