设置embed的透明度
wmode="transparent"
<embed src="http://player.youku.com/player.php/sid/XODA2MjM4NjM2/v.swf" width="100%" height="document.body.clientWidth/1.7" allowFullScreen="true" quality="high" align="middle" allowScriptAccess="always" type="application/x-shockwave-flash" wmode="transparent">