slide不滚动是怎么回事

<div class="he-box">
  <h2>{dede:type typeid=7}<a href="[field:typelink/]" rel="nofollow" title="[field:typename/]">[field:typename/]</a>{/dede:type}</h2>
    <P>SUCCESSFEL CASES</P>
  <div class="he-b">
    <div class="mr_box">
      <div class="he">
        <ul>
          {dede:arclist typeid=7 row='5'}
            <li><a href="[field:arcurl/]"  rel="nofollow" title="[field:title/]"><img src="[field:litpic/]"  alt="[field:title/]" title="[field:title/]"/><spen>[field:title/]</spen></a></li>
          {/dede:arclist}
        </ul>
      </div>
    </div>
    <script language="javascript">
         jQuery(".he-b  .mr_box").slide({titCell:"",mainCell:".he ul",autoPage:true,effect:"leftLoop",autoPlay:true,vis:4});
        </script> 
  </div>
</div>

不知道什么原因，不滚动，还变成了两行

这个要针对块元素才能滚动