CSS定位的问题
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="daiban.aspx.cs" Inherits="daiban" Theme="moren" %>
<!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>待办事宜</title>
<style type="text/css">
<!--
#bt {
position : static;
width:800px;
height:50px;
z-index:1;
text-align :center;
font-size:14pt;
margin-left:auto;
margin-right:auto;
}
#lctb {
position : static;
width:800px;
height:250px;
z-index:2;
overflow: scroll;
border-right: #0099ff 1px solid;
border-top: #0099ff 1px solid;
border-left: #0099ff 1px solid;
border-bottom: #0099ff 1px solid;
margin-left:auto;
margin-right:auto;
}
-->
</style>
</head>
<body style="font-size:9pt;" >
<form id="form1" runat="server">
<div id="bt">
<br />
待 办 事 宜</div>
<div id="lctb">
<span style="color: #ff3333">
流入人员对方通报</span><asp:Label ID="Label1" runat="server" Text="Label"></asp:Label><br />
<asp:GridView ID="gvlctb" runat="server" Width="774px" OnPageIndexChanging="gvlctb_PageIndexChanging" AutoGenerateColumns="False">
<Columns>
<asp:TemplateField HeaderText="打开">
<ItemTemplate>
<asp:LinkButton ID="lblctb" OnCommand="lblctb_Command" runat="server" CommandArgument='<%# Eval("bh") %>'
Text='<%# "打开" %>'></asp:LinkButton>
</ItemTemplate>
</asp:TemplateField>
<asp:BoundField DataField="tbrq" HeaderText="通报日期" />
<asp:BoundField DataField="dw1" HeaderText="通报单位" />
<asp:BoundField DataField="fnxm" HeaderText="妇女姓名" />
<asp:BoundField DataField="zfxm" HeaderText="丈夫姓名" />
<asp:BoundField DataField="bh" HeaderText="通报单编号" />
</Columns>
</asp:GridView>
</div>
</form>
</body>
</html>
上面的代码实现居中,第一次显示时实现了居中,但一旦打开其中链接后,就不居中了,请高手帮忙。