jsp传对象参数到action中，action中set方法的参数为null对象，是什么情况

 function checkClaimVoucher(checkResult){
                if(!confirm('确定'+checkResult+'报单吗')) return;
                document.getElementById("result").value = checkResult;

                document.checkResultForm.submit();
            }

 <s:form action="checkResult_checkClaimVoucher" name="checkResultForm" method="POST">
    <table width="90%" border="0" cellspacing="0" cellpadding="0" class="addform-base">
        <tr>
            <td>
                审批意见：
            </td>
        </tr>
        <tr>
            <td>
                <textarea name="" id="textarea" cols="45"
                    rows="5"></textarea>
            </td>
        </tr>
         <!--表单提交行-->
         <tr>
            <td colspan="3" class="youbing">
            <s:hidden  name="claimVoucher.id" value="<s:property value='claimVoucher.id'/>"/>
                <s:hidden id="result" name="claimVoucher.status" value=""/>
                <input type="button" name="claimVoucher.status" id="button" value="审批通过"
                    class="submit_01" onclick="checkClaimVoucher('通过')" />
                <%-- <s:hidden id="claimId" name="checkResult.claimId" value="%{claimVoucher.id}"/> --%>
                <s:if test='#session.employee.positionId != 4'>
                    <input type="button" name="claimVoucher.status" id="button" value="审批拒绝"
                        class="submit_01" onclick="checkClaimVoucher('拒绝')" />
                    <input type="button" name="claimVoucher.status" id="button" value="打回"
                        class="submit_01" onclick="checkClaimVoucher('打回')" />
                </s:if>

            </td>
         </tr>
    </table>
    </s:form>

没有action 目测重名了