<s:if?test="#session.user?==?null">??
????<div?class="login">??
????????<ul>??
????????????<li?id="diagx"><a?href="#">On-Demand?Login</a></li>??
????????????<li><a?href="#">Support</a></li>??
????????</ul>??
????????<a?href="#"?class="join-now-top"><img?src="/TitanMen/images/join-now.gif"?alt="Join?NOW!"?/></a>??
????</div>??
</s:if>??
<s:else>??
????????<div?class="login">??
????????????<ul>??
????????????????<li><a?href="#">My?Account</a></li>??
????????????????<li><a?href="#">Support</a></li>??
????????????</ul>??
????????????<a?href="#"?class="logout-top"><img?src="/TitanMen/images/btn-logout.gif"?alt="Log?Out!"?/></a>??
????????</div>??
</s:else>

通過在test里判斷就可以了，跟if else用法差不多，就是書寫上有些區別！

<s:if test="xxxx">

xxxx代表條件判斷，可用值棧里的值寫表達式，表達式為真時顯示<s:if></s:if>中的內容