<%String classon=text.dealNull(request.getParameter("classon"),"0");
request.getSession().setAttribute("classon",classon);

 %>

 <s:set name="myValue" value="#session.classon" />
 
    <s:iterator  value="#session.listA" status="courseType" >
   
      <li id="<s:property value="mainid" />" <s:if test="%{#courseType.index==#myValue}"> class="on" </s:if>
>
      <a href="javascript:gotoson('<s:property value="mainid" />','<s:property value="#courseType.index" />');">
   <s:property value="name" /></a></li>

         </s:iterator>

如果是request接收過來的

     <%String cmid=text.dealNull(request.getParameter("coursecontentID"),"");
       //out.print(cmid);
       request.setAttribute("cmid",cmid);
       %>
        <s:set name="cmid" value="#request.cmid" />
       
      <select id="contentID" name="coursecontentID" onchange="selectzj()">
       <s:if test="#request.CourseContents[0] != null">
        <s:iterator  value="#request['CourseContents']"  status="cct" id="content">
    <option value="<s:property value="mainid" />" <s:if test="%{#content.mainid==#cmid}"> selected="selected" </s:if> ><s:property value="lessonName"  escape='false' /></option>        
    </s:iterator>
    </s:if>

這樣就行了