求一正则

<h3 class="summary"><a href="http://item.taobao.com/auction/item_detail-0db2-78457a24fb8c8079854294fdc1b31475.jhtml"  target=_blank class="EventCanSelect">索尼爱立信 W900c 9.99成新</a></h3>
<div class="photo">
<a href="http://item.taobao.com/auction/item_detail-0db2-78457a24fb8c8079854294fdc1b31475.jhtml"  target=_blank><span><img src="http://img04.taobaocdn.com/bao/uploaded/i4/T1UaNbXadckwC7wA7._112915.jpg_sum.jpg" class="hesper:small2big" /></span></a>
</div> 
    <ul class="attribute">                        
<li class="dtlisted"><span>剩余</span>7分钟</li>
<li class="place">广东广州</li>
<li class="shipping">10.00</li>
<li class="legend"><a href="http://www.taobao.com/cn/theme/site/xiaobao_7tian_20080912_080916.php" class="legend-returned" title="消费者保障服务，提供7天无理由退换货" target="_blank"><span>此商品支持7天无理由退货</span></a>
    </li>
<li class="price">一口价<em>1100.00</em></li>
    </ul>
现用PHP获取网页内容，要取红色字体的数据，请问用正则怎么过滤？多谢！