选中与修改

       <s:form action="okupdateByIdAction" method="post">
    <s:textfield name="user.id" value="%{#request.users.id}" label="学号"/><br>
    <s:textfield name="user.name" value="%{#request.users.name}" label="姓名"/><br>
  

    <s:radio list="{'男','女'}" name="user.sex" label="性别"   value="%{#request.users.sex}" id="nan"/>
    
    <br>
     <s:checkboxlist name="user.hoby" list="{'看书','足球','篮球','排球','游泳','网球'}" id="user.hoby" label="爱好" value="%{#request.users.hoby}"/>
     <br>   
 
    <s:select label="籍贯" id="user.city" name="user.city" list="{'北京','上海','天津','福建','云南'}"

       headerKey="-1" headerValue="请选择您的城市" value="%{#request.users.city}"/>
   
     <br>
    <s:submit value="修改"/>
    </s:form>


  
<script type="text/javascript" >
  

 var b=document.getElementsByName('user.sex');
  var bb='%{#request.users.sex}';
 
 
for(var i=0;i<b.length;i++){
if(b[i].value==bb){