求一正则表达式

Question

<?php
$content = '<div id="memberflat" class="titlebar">
              <div class="drawsidetow">会员平台</div>
              <div class="smalltitle">为何注册?</div>
            </div>
            <hr /> 
            <link rel="stylesheet" href="a/1.css" type="text/css"media="screen" />
            <link rel="stylesheet" href="a/2.css" type="text/css" media="screen" />';
$pattern = "/<link[^>]*>/";
$new_content = preg_replace($pattern,'',$content);
?>