<script language="javascript"> 
var flag = 0; //控制变量放在函数内起不到作用.
function openplay() 
{ 
if(flag==0){ 
var em = document.createElement("embed"); 
em.autostart="1" ;
em.src="mp3/hh.mp3";   //路径,地址中不用反杠,用顺杠
document.documentElement.appendChild(em); 
flag=1; 
} 
} 
</script> 
<a href=# onclick="openplay()">播放</a>