ModalPopupExtender1.Show();窗口无法弹出
<asp:UpdatePanel ID="UpdatePanel1" runat="server" >
<ContentTemplate>
<asp:ModalPopupExtender TargetControlID="HiddenField1" BackgroundCssClass="bg" PopupControlID="Pan_tan" ID="ModalPopupExtender1" runat="server">
</asp:ModalPopupExtender>
<asp:HiddenField ID="HiddenField1" runat="server" />
<asp:Panel ID="Pan_tan" runat="server" Width="100%" Style="display: none">
<table style=" width:500px;" class="modalPopup-text">
<tr>
<td colspan="4">
<strong>用户订单操作</strong></td>
</tr>
<tr>
<td align="right" style="width: 100px">
接收情况:</td>
<td align="left" style="width: 100px">
<asp:RadioButton ID="Radio_Y" runat="server" GroupName="aa"
Text="同意接收" /></td>
<td style="width: 100px" align="left">
<asp:RadioButton ID="Radio_N" runat="server" GroupName="aa"
Text="不同意接收" /></td>
<td style="width: 100px">
</td>
</tr>
</table>
</asp:Panel>
后台代码:
ModalPopupExtender1.Show();
现在遇到的问题是遮罩层始终不弹出来,麻烦各位帮帮忙了!