jquery 绑定的事件触发不了，求指教
jQuery 代码：
$(document).ready(function(){
$("#tbUserName").bind("change",function(){
$.ajax({
type:"Get",
url:"/AjaxPages/AjaxCodes.aspx",
dataType:"JSON",
data:"userName="+$("#tbUserName").val()+"&flg=username",
success:function(msg)
{
$("[id$=lbCheckUserName]").html(msg);
}
});
});

$("#tbPassword").bind("change",function(){
var reg=/^[0-9]{6,}$/;
var password=$("#tbPassword").val();
if(password.match(reg)==null)
{
$("#lbCheckPassword").text("error");
}
else
{
$("#lbCheckPassword").text("OK");
}
});
});

asp 页面：
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="UserRegister.aspx.cs" Inherits="MyBookShop.UserPages.UserRegister"
MasterPageFile="~/MasterPages/index.Master"%>

<asp:Content ID="content2" runat="server" ContentPlaceHolderID="head">
<script type="text/javascript" src="../js/jquery-1.3.2-vsdoc2.js"></script>
<script type="text/javascript" src="../js/JCheckInfo.js"></script>


</asp:Content>

<asp:Content ID="content3" runat="server" ContentPlaceHolderID="ContentPlaceHolder1">
<table>
<tr>
<td>
<asp:Label ID="Label1" runat="server" Text="用户名"></asp:Label>
</td>
<td>
<input id="tbUserName" type="text" />
</td>
<td>
<asp:Label ID="lbCheckUserName" runat="server" Text=""></asp:Label>
</td>
</tr>
<tr>
<td>
<asp:Label ID="Label3" runat="server" Text="密码"></asp:Label>
</td>
<td>
<asp:TextBox ID="tbPassword" runat="server"></asp:TextBox>
</td>
<td>
<asp:Label ID="lbCheckPassword" runat="server" Text=""></asp:Label>
</td>
</tr>
<tr>
<td>
<asp:Label ID="Label5" runat="server" Text="确认密码"></asp:Label>
</td>
<td>
<asp:TextBox ID="tbConfirmPassword" runat="server"></asp:TextBox>
</td>
<td>
<asp:Label ID="lbCheckConfirmPassword" runat="server" Text=""></asp:Label>
</td>
</tr>
<tr>
<td>
<asp:Label ID="Label7" runat="server" Text="真实姓名"></asp:Label>
</td>
<td>
<asp:TextBox ID="tbRealName" runat="server"></asp:TextBox>

</td>
<td>
<asp:Label ID="lbCheckRealName" runat="server" Text=""></asp:Label>
</td>
</tr>
<tr>
<td>
<asp:Label ID="Label9" runat="server" Text="联系方式"></asp:Label>
</td>
<td>
<asp:TextBox ID="tbPhone" runat="server"></asp:TextBox>
</td>
<td>
<asp:Label ID="lbCheckPhone" runat="server" Text=""></asp:Label>
</td>
</tr>
<tr>
<td>
<asp:Label ID="Label11" runat="server" Text="联系地址"></asp:Label>
</td>
<td>
<asp:TextBox ID="tbAddress" runat="server"></asp:TextBox>
</td>
<td>
<asp:Label ID="lbCheckAddress" runat="server" Text=""></asp:Label>
</td>
</tr>
<tr>
<td>
<asp:Button ID="btnSubmit" runat="server" Text="提交" />
</td>
<td>
</td>
<td>
</td>
</tr>
<tr>
<td>
<asp:Label ID="lbCheckSubmitInfo" runat="server" Text=""></asp:Label>
</td>
<td>
</td>
<td>
</td>
</tr>
</table>
</asp:Content>

用户名的那个是好使的，但是
密码那个绑定的事件触发不了，请各位帮小弟看看代码哪里有问题？
看了一上午了，没有头绪

[解决办法]
要么就用

HTML code

 $('input[id$="tbPassword"]')
[解决办法]
你的"用户名文本框"是使用的是原生的html标签（所谓的html控件）。而你的"密码框"使用的是服务端控件。
HTML code
<input id="tbUserName" type="text" />  <asp:TextBox ID="tbPassword" runat="server"></asp:TextBox>