ext查询刷新grid数据

输入查询条件，让grid数据刷新。怎么实现？
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<%@page contentType="text/html; charset=utf-8" %>

<%
String query = (String)request.getAttribute("query");

<script  type="text/javascript">
this.focus();
var gridmorebook;
var store2;
Ext.onReady(function(){
//创建http请求代理
var proxy=new Ext.data.HttpProxy(  {url:'/rmbcs/xs03.op?method=salesList&query=<%=query%>'}); 
// 创建解析对象用于解析后台json数据格式
var reader = new Ext.data.JsonReader({
    fields: [
       {name: 'salesid',type:'string'},
       {name: 'poser',type:'string'},
       {name: 'netprice', type: 'string'},
       {name: 'mrsaleprice', type: 'string'},
       {name: 'amount', type: 'string'},
       {name: 'scalar', type: 'string'},
       {name: 'payway', type: 'string'},
       {name: 'updatetime', type: 'string'}
    ]
  });
//创建数据源
store2 = new Ext.data.Store({
   proxy:proxy,
   reader:reader
});
store2.load();
//创建表格，以store2为数据源来填充表格
gridmorebook = new Ext.grid.GridPanel({
    //deferRowRender:false,
    store: store2,
    columns: [
        {header: "销售单编号", width: 140, sortable: true, dataIndex: 'salesid',align:'center'},
       // {id:'salesid',header: "销售单编号", width: 160,  dataIndex: 'id',align:'center'},
        {header: "收银员", width: 120,  dataIndex: 'poser',align:'center'},
        {header: "销售码洋", width: 100,  dataIndex: 'netprice',align:'center'},
        {header: "销售折扣", width: 120,   dataIndex: 'mrsaleprice',align:'center'},
        {header: "销售实洋", width: 100,   dataIndex: 'amount',align:'right'},
        {header: "销售数量", width: 100,   dataIndex: 'scalar',align:'right'},
        {header: "支付方式", width: 80,   dataIndex: 'payway',align:'right'},
        {header: "销售日期", width: 100,   dataIndex: 'updatetime',align:'right'}

    ],

    height:400,
    width:860,
    header: false


});

gridmorebook.render('gridDiv2');

});
function search(){
if(event.keyCode==13){//Enter
store2.reload();
}
}

图书条码：销售日期：书名：

[code="js"]store2.reload({
params : {
'参数一':'value',//或者是变量
'查询条件':'value2'
}
})[/code]

直接让grid的store按条件重新加载数据就可以了

输入查询条件之后，用ajax去后台取数据，返回数据后，更新grid嘛

使用 beforeload 绑定请求的参数的