<pre><code>

<a class="list_catalog" onclick="setCookie('id_news', <?=$arFields["ID"];?>);"  href="/news/"><span id="test">Новости</span></a>

    <?}elseif($_COOKIE['id_news']==$arFields["ID"]){?>

    <a class="list_catalog"  href="/news/">Новости</a>

<?}?>
                <?}else{?> <a class="list_catalog"  href="/news/">Новости</a>
                <?}?>