<script>
function download()
{
//下载文件的地址
var url="http://music.baidu.com/data/music/file?link=http://zhangmenshiting.baidu.com/data2/music/13618994/13618995183600128.mp3?xcode=48d4a720fcd9a974586066d0145f7207";
document.getElementById("ifile").src=url;
}
</script>
<a href="#" onclick="download()">download</a>
<iframe id="ifile" style="display:none"></iframe>