easyui 放到js方法里就没用

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="index.aspx.cs" Inherits="TEST2.index" %><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
    <link rel="stylesheet" type="text/css" href="Styles/themes/default/easyui.css">
<link rel="stylesheet" type="text/css" href="Styles/themes/icon.css">
    
<style type="text/css">html,body{margin:0px;padding:0px;font-size:12px;height:100%;}
#login{ text-align:center;}
#login h3{color:#1776CA;font-size:25px;}
#search{ background:#FFF0F5 ; border:1px #A9CAE5 solid; height:40px; padding:5px;  line-height:40px; margin-top:10px; width:980px; text-align:left;margin:auto;}
#main{ margin-left:auto;margin-right:auto; width:990px; margin-top:10px;}
</style>
</head>
<body>
    <form id="form1" runat="server">
   <div id="header">
<div id="login">
<h3>规划项目</h3>
</div>
<div id="search">
<table width="980" cellpadding="0px" cellspacing="0px" border="0px">
<tr>
<td width="70">所在地区:</td>
<td width="120"><asp:DropDownList ID="DropDownList1" runat="server" Width="120">
    <asp:ListItem Selected="True">全省</asp:ListItem>
    <asp:ListItem>杭州</asp:ListItem>
    <asp:ListItem>金华</asp:ListItem>
    </asp:DropDownList>
</td>   
<td width="50">&nbsp</td>
<td width="80">项目名称:</td>
<td width="150">
    <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox></td>
    <td width="50">&nbsp</td>
   <td width="80">
        <asp:Button ID="Button1" runat="server" Text="搜索"/></td>
        <td width="80"><asp:Button ID="Button2" runat="server" Text="导出" /></td>
        <td width="300">&nbsp</td>
</tr>
</table>
</div>
<div id="main">
<table id="dg" class="easyui-datagrid" >  
     
    <thead>  
        <tr>          
            <th field="city" width="200">市</th>  
            <th field="xian" width="200">县</th>  
            <th field="xmmc" width="200">项目名称</th>  
            <th field="ghmc" width="200">规划名称</th>  
            <th field="xmlx" width="200">项目类型</th>  
             <th field="qqjzqk" width="230" align="center">前期进展情况</th>  
     
            
        </tr>          
    </thead>  
   
</table> </div>
<script type="text/javascript" src="Scripts/jquery-1.7.2.min.js"></script>
<script type="text/javascript" src="Scripts/jquery.easyui.min.js"></script>       <script src="Scripts/easyui-lang-zh_CN.js" type="text/javascript"></script>
<script type="text/javascript">
    $(document).ready(function () {
        start();
        $("#Button1").click(function () {
            search();
        });
    });    $("#dg").datagrid(
{
    url: 'DataHandler1.ashx?city1=hangzhou &xm1=hangzhou',
//        url: 'DataHandler1.ashx?city1='+city+'&xm1='+xm,
    width: 990,    pageNumber: 1,
    pageSize: 20,
    pageList: [20, 40, 60],
    height: 400,
    fitColumns: true,
    rownumbers: true,
    pagination: true,
    collapsible: true,
    sortName: 'no',
    sortOrder: 'asc'
}
) 
    function start() {
    }
function search() {
    var ddl = document.getElementById("DropDownList1")
    var index = ddl.selectedIndex;    var city = ddl.options[index].value;
    var xm = $('#TextBox1').val();    $("#dg").datagrid(
{
    url: 'DataHandler1.ashx?city1=hangzhou &xm1=hangzhou',
//    url: 'DataHandler1.ashx?city1='+city+'&xm1='+xm,
    width: 990,
   
    pageNumber: 1,
    pageSize: 20,
    pageList: [20, 40, 60],
    height: 400,
    fitColumns: true,
    rownumbers: true,
    pagination: true,
    collapsible: true,
    sortName: 'no',
    sortOrder: 'asc'
}
)
  }</script>    </form>
   
</body></html>
如果  $("#dg").datagrid那段代码放到外面能显示数据。但是如果放到方法start()里面，DataHandler1.ashx能读取到数据，但是表格里显示不出来。search方法里一样。有人碰到过一样的情况吗
放到外面
放到方法里面求好心人帮忙。。正在实习，搞不出来烦躁