How to use s:iterator s:include s:param

[albert kao]

This display properly:
<s:if test="#session.response.items.itemList">
  <s:iterator value="#session.response.items.itemList">
    <s:property value="description"/>
  </s:iterator>
</s:if>

I refactor to the following two files, which display nothing.
I have other codes in items.jsp which confirms that items.jsp is being used
in showitems.jsp.
Please help.
Thanks.

items.jsp:
<s:set var="itemList" value="%{parameters.itemList}"/>

<s:if test="%{itemList}">
  <s:iterator value="%{parameters.itemList}">
    <s:property value="description"/>
  </s:iterator>
</s:if>



showitems.jsp:
<s:include value="items.jsp">
  <s:param name="itemList" value="#session.response.items.itemList"/>
</s:include>