为什么我的模式的对话框不能覆盖后面的控件

[jiaojian_08]

我是在IE8里跑的，说白了就是没有图层
我的代码
<cc1:ModalPopupExtender ID="ModalPopupExtender1" runat="server"
TargetControlID="Button3"
PopupControlID="Panel1"
DropShadow="true"
Drag="false"
RepositionMode="None">
</cc1:ModalPopupExtender>
<asp:Button ID="Button3" runat="server" Text="Button" />
<asp:Button ID="Button4" runat="server" Text="Button" OnClick="Button4_Click" />
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
<asp:Panel ID="Panel1" runat="server" BackColor="Lavender">
<asp:Label ID="Label1" runat="server" Text="用户名"></asp:Label>
<asp:TextBox ID="txtLoginId" runat="server"></asp:TextBox>
<br />
<asp:Label ID="Label2" runat="server" Text="密码"></asp:Label>
<asp:TextBox ID="txtLoginPwd" runat="server"></asp:TextBox>
<br />
<asp:Button ID="Button1" runat="server" Text="登录" />
<asp:Button ID="Button2" runat="server" Text="注册" /></asp:Panel>


我帮解决下

[jiaojian_08]

???

[jiaojian_08]

[nosuchtracter]

不知道楼主的代码里面哪里体现了模式对话框？

[jiaojian_08]

ModalPopupExtender控件 这个不是asp。net的模式对话框吗