strut1 怎么与EXT 做交互。ActionForm在里面的作用。给我一个例子吧！

如题：[code="java"]

Ext.onReady(function() {
var sm = new Ext.grid.CheckboxSelectionModel();
// //定义一个ColumnModel，表头中有四列
var cm = new Ext.grid.ColumnModel([
{header:'编号',dataIndex:'id'},
{header:'名称',dataIndex:'name'},
{header:'描述',dataIndex:'descn'}
]);

var ds = new Ext.data.Store({
proxy: new Ext.data.HttpProxy({url:'employee.do?method=queryall'}),
autoLoad : true,
reader: new Ext.data.JsonReader({
totalProperty: 'totalProperty',
root: 'root'}, [ {name: 'id'}, {name: 'name'}, {name: 'descn'}])});

var grid = new Ext.grid.GridPanel({
el: 'grid',
ds: ds,
cm: cm,
bbar: new Ext.PagingToolbar({ pageSize: 10, store: ds, displayInfo: true, displayMsg: '显示第 {0} 条到 {1} 条记录，一共 {2} 条', emptyMsg: "没有记录" })
});
ds.load({params:{start:0,limit:10}});
grid.render();

});
[/code]
[code="java"]
public ActionForward queryall(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response)
throws Exception {
System.out.println("-----------------");
int totalProperty = employeeDao.totalRecord();
int start;

try {

start = Integer.parseInt(request.getParameter("start"));

} catch (NumberFormatException e1) {

start = 0;

}

int limit;

try {

limit = Integer.parseInt(request.getParameter("limit"));

} catch (NumberFormatException e1) {

limit = 2 ;

}

if(start>0)

start = start/limit;

//Hibernate级联时,用json有错误,要把被级联的那个对象干掉,这样就没法显示被级联的对象了

// JsonConfig conf = new JsonConfig();

// conf.setExcludes(new String[]{"newstype"});

      List list = employeeDao.queryAll(start, limit);   
      JSONArray jsonArray = new JSONArray();   
      Iterator ite = list.iterator();   
    //对list转变成的ite进行遍历，得到每个对象，并put到map里，再把map放到json数组里   
      while(ite.hasNext()){   
       Employee news = (Employee) ite.next();   
       Map map = new HashMap();   
       map.put("id", news.getId());   

       map.put("name", news.getName());   
       map.put("descn", news.getDescn());   
       jsonArray.add(map);   
      }       
      String jsonStr = jsonArray.toString();   
    //为了分页，要加上start,limit,totalProperty,下面的符合json数据的形式   
      String jsonString = "{start:"+start+",limit:"+limit+",totalProperty:"+totalProperty+",newsList:"+jsonStr+"}";   
     System.out.println("-----------------"+jsonString);
      response.setContentType("text/html;charset=utf-8");     
      try {   //输出来，到jsp页面调用   
       response.getWriter().write(jsonString);   
      } catch (IOException e) {      
       e.printStackTrace();   
      }   
      return null;//返回null   
     }   

[/code]

Ext 没有进入Action 中去数据！