jsp页面出NullPointerException

这个页面一直报NullPointerException,不知道怎么回事,请大家帮忙看一下,谢谢,代码:
<%@ page language="java" pageEncoding="UTF-8"%>
<%@ include file="/jsp/common/tag_declaration.jsp" %>
<%@ include file="/jsp/common/header.jsp" %>
<%-- 自定义JS脚本区域：开始 --%>
<script type="text/javascript">
function query(form,actionPath){
var startDate = form.startDate.value;
var endDate = form.endDate.value;
if(LTrim(startDate)==""){
     alert("起始日期为必添项！");
     form.startDate.focus();
     return false;
} else if(LTrim(endDate)==""){
     alert("终止日期为必添项！");
     form.endDate.focus();
     return false;
}
startDate = startDate.replace(/\-/g,"");
endDate = endDate.replace(/\-/g,"");
if(startDate > endDate){
alert("终止日期不能小于起始日期！");
return false;
}
gotoAction(form, actionPath);
}
function listView(form){
var count = getSelectedItemCount('selectItems');
if(count != 1){
alert("请选择一家店进行明细查看！");
return false;
}
gotoAction(form, '/saTimesCountFilterUIAction.do?method=listView');

}
// 全部选择  
function chooseForAll(){
for(var i = 0; i < document.getElementsByName('selectItems').length; i++){
document.getElementsByName('selectItems')[i].checked = true;
}
}
// 全部取消
function cancelForAll(){
for(var i = 0; i < document.getElementsByName('selectItems').length; i++){
document.getElementsByName('selectItems')[i].checked = false;
}
}
</script>
<%-- 自定义JS脚本区域：结束 --%>
<html:form action="/saTimesCountFilterUIAction.do" method="post">
<div id="zsjt-main">
  <div class="main-inner-layout">
<jsp:include page="/jsp/common/tree.jsp"></jsp:include>
    <div class="split-bar"></div>
    <div class="data-view-title">
      <img src="<bean:write name="basePath"/>/images/main-data-view-title-tip.png" width="9" height="9" />
      <span>SA台次营业额统计</span>
    </div>
    <div class="data-view-query">
      <%-- 查询操作区域：开始 --%>
      <label>
起始日期<bean:message key='common.lbl.colon' bundle='common'/>
       <html:text name="saTimesCountFilterUIForm" property="startDate" size="10" onfocus='WdatePicker({isShowClear:false})' readonly="true" />
      </label>
      <label>
终止日期<bean:message key='common.lbl.colon' bundle='common'/>
       <html:text name="saTimesCountFilterUIForm" property="endDate" size="10" onfocus='WdatePicker({isShowClear:false})' readonly="true" />
      </label>
      <button name="saTimesCountFilterUI.query" onclick="query(document.saTimesCountFilterUIForm, '/saTimesCountFilterUIAction.do?method=query')">
       <img src="<bean:write name="basePath"/>/images/easicon/tbtn_find.gif" width="16" height="16" />
       <span><bean:message key='common.btn.search' bundle='common'/></span>
      </button>
      <%-- 查询操作区域：结束 --%>
    </div>
    <div class="data-view-toolbox">
      <%-- 按钮操作区域：开始 --%>
      <button name="saTimesCountFilterUI.chosseForAll" onclick="chooseForAll()">
       <img src="<bean:write name="basePath"/>/images/easicon/tbtn_selectall.gif" width="16" height="16" />
       <span>全选</span>
      </button>
      <button name="saTimesCountFilterUI.cancelForAll" onclick="cancelForAll()">
       <img src="<bean:write name="basePath"/>/images/easicon/tbtn_clearall.gif" width="16" height="16" />
       <span>全清</span>
      </button>
      <button name="saTimesCountFilterUI.listView" onclick="listView(document.saTimesCountFilterUIForm)">
        <img src="<bean:write name="basePath"/>/images/easicon/tbtn_new.gif" width="16" height="16" />
       <span>明细</span></button>
      <%-- 按钮操作区域：结束 --%>
    </div>
    <div class="data-view">
      <div id="sortableTableHeadDiv">
        <table id="sortableTableHeadTable" border="0" cellpadding="0" cellspacing="0" class="head-view">
          <%-- 标题：开始 --%>
          <tr>
            <td nowrap="nowrap">&nbsp;</td>
<td nowrap="nowrap">店号</td>
<td nowrap="nowrap">店名</td>
          </tr>
          <%-- 标题：结束 --%>
        </table>
      </div>
      <div id="sortableTableDetailDiv">
        <table id="sortableTableDetailTable" border="0" cellpadding="0" cellspacing="0" class="sortable detail-view">
          <%-- 数据：开始 --%>
          <logic:notEmpty name="saTimesCountFilterUIForm" property="list">
  <logic:iterate name="saTimesCountFilterUIForm" property="list" id="item">
          <tr>
            <td nowrap="nowrap"><html:radio name="item" property="selectItems" value="${item.storeId}"/></td>
            <td nowrap="nowrap"><bean:write name="item" property="storeNumber" /></td>
<td nowrap="nowrap"><bean:write name="item" property="storeName" /></td>
          </tr>
          </logic:iterate>
  </logic:notEmpty>
          <%-- 数据：结束 --%>