discuz! 门户列表页随机封面缩略图代码

<!--{if $value[pic]}-->
<div class="atc"><a href="$article_url" target="_blank"><img src="$value[pic]" alt="$value[title]" class="tn" /></a></div>
<!--{else}-->
<!--{eval $picname = rand(1,10);}-->
<div class="atc"><a href="$article_url" 
target="_blank"><img src="static/ranimg/cover_{$picname}.jpg" alt="$value[title]"
class="tn" /></a></div>
<!--{/if}-->