struts 反选 删除 问题

Question

复选框 一条记录的时候 点“全部选中/反选”能选中 但再点就不反选了 多条记录都好用代码如下：
<script language="javascript">
    function choose(){
       if(ushanchuForm.xuanze.length == null){
      ushanchuForm.xuanze.checked = "checked";
       }
       for(i=0;i<ushanchuForm.xuanze.length;i++){
         if(!ushanchuForm.xuanze[i].checked){
            ushanchuForm.xuanze[i].checked = true;
           }
          else{
            ushanchuForm.xuanze[i].checked = false;
           }
       }
    }
    ...........表单中：
  <logic:iterate id="users" name="findlist">
  <tr>
    <td><div align="center">
    
      <html:multibox property="xuanze" value="${users.userid}"/>
          </div></td>
    <td><div align="center"></div>${users.truename}</td>
<td><div align="center"></div>${users.age}</td>
<td><div align="center"></div>${users.deptid}</td>
<td><div align="center"></div>${users.position}</td>
    <td width="40"><div align="center"><a href="jsp/user/Uxiugai.jsp">修改</a></div></td>
<td width="99"><div align="center"><html:button property="" value="删除" onclick="return send('uremove.do?userid='+${users.userid});"/></div></td>
  </tr>
  </logic:iterate>
  
  <tr>
    <td colspan="5">
<div align="center"></div>
<div align="left">
  <html:button property="" value="全部选中/反选" styleClass="t" onclick="choose();"/>
  <html:submit value="删除选中记录" styleClass="t" />
</div>
<div align="center"></div></td>
    </tr>
</table>
</html:form>

Answer 1

        if(!ushanchuForm.xuanze[i].checked){ 
            ushanchuForm.xuanze[i].checked = true; 
          } 
          else{ 
            ushanchuForm.xuanze[i].checked = false; 
          } 这个ushanchuForm.xuanze[i].checked = !ushanchuForm.xuanze[i].checked