div piao置于div bg之上

<div class="bg">
<div class="piao" style="background:url(skin/images2/department/jxdt.png) no-repeat;line-height:28px;">教学动态</div>
</div>

css

.piao {position:absolute;left:15px;top:-12px;width:86px;height:31px;text-align:center;line-height:24px;color:#fff;font-weight:bold;}

.bg {width:324px;height:288px;background-color:#fff;margin:20px 8px 9px 7px;position:relative;}

将一个div置于另一个div之上