Modal Popup extender does not work when "OK" or "Cancel" button clicked
i have 2 panels.. i used model popup extender
<div style="background-position: 99% 7px; cursor:pointer">
<asp:Panel runat="server" ID="RootPanel" CssClass="panel" >
<p> <asp:Label ID="Nameh" runat ="server" Text ="Name: "></asp:Label>
<asp:Label ID="Name" runat ="server" Text ="Variable Text "></asp:Label> </p>
</asp:Panel>
</div>
<asp:Panel runat="server" ID="ChildPanel" CssClass="ModelPopupPanel">
<p><label>Name: </label><asp:TextBox ID="TbxName" runat="server" CssClass="tb5"></asp:TextBox></p>
<p><asp:Button runat="server" ID="DoneButton" Text="Done" CssClass="btn">
<asp:Button runat="server" ID="btnCancel" Text="Cancel" CssClass="btn" /> </p>
</asp:Panel>
<asp:ModalPopupExtender ID="AddressRootPanel_ModalPopupExtender" runat="server" BackgroundCssClass="ModelBackground"
DynamicServicePath="" Enabled="True" TargetControlID="RootPanel"
PopupControlID="ChildPanel" DropShadow="True" CancelControlID="btnCancel"
ViewStateMode="Enabled" />
Popup works fine at first when i click on the RootPanel (which is targetControlID of ModalPopupExtendar ).
But problem is when ChildPanel popup and i click on "btnCancel", ChildPanel get closed
and Next time it does not Popup as it did first time ??? Please help