循环栏目栏目及文章调用已成功,但如何实现左右浮动??如下图怎么写判断代码?求解!

<div class="box columnBar fl">
         <div class="hd"><a target="_blank" href="[KS:ClassLink]" class="more">更多</a><h4><span>
      <a target="_blank" href="[KS:ClassLink]">[KS:ClassName] </a>
     </span></h4></div>
                        <div class="bd">
                            <ul class="topicList">
   [KS:List]
    [!--looplist--]
   [/KS:List]
   </ul></div></div>

(以上蓝色部分为外循环代码  其中CSS中,"F1"为左浮动,有个右浮动为"fr"已写好,但这里怎么去判断呢?)

[Loop Times="1"]
<li class="t"><div class="pic"><a target="_blank" href="{$Field(InfoID,url,0,3)}" title="{$Field(Title,text,0,...,2,)}"><img src="{$Field(DefaultPic,text,0,...,2,/sysimg/nopic.gif)}"></a></div><div class="con"><div class="title"><a title="标题：{$Field(Title,text,0,...,2,)}
点击数：{$Field(Hits,text,0,...,2,)}
发表时间：{$Field(AddDate,date,YY-MM-DD)}" target="_blank" href="{$Field(InfoID,url,0,3)}" class="tit">{$Field(Title,text,16,...,2,)}</a></div><div class="intro">{$Field(Intro,text,35,...,2,)}<a target="_blank" href="{$Field(InfoID,url,0,3)}" class="more">[详细]
</a></div></div></li>[/Loop]
[Loop Times="4"]<li class="n"><div class="title"><span class="date">{$Field(AddDate,date,MM-DD)}</span><img alt="推荐" src="/images/common13.gif"><a title="标题：{$Field(Title,text,0,...,2,)}
点击数：{$Field(Hits,text,0,...,2,)}
发表时间：{$Field(AddDate,date,YY-MM-DD)}" target="_blank" href="{$Field(InfoID,url,0,3)}" class="tit">{$Field(Title,text,20,...,2,)}</a></div></li>
[/Loop]