PopupElementID and nested popup controls

Hello Andy,

It seems that you can handle the PopupElementResolve event for this purpose. Note that I've also modified the CloseAction property's value of the ASPxPopupControl1:

        <dxe:ASPxButton ID="ASPxButton1" runat="server" Text="ASPxButton" AutoPostBack="False">
        </dxe:ASPxButton>
        <dxpc:ASPxPopupControl ID="ASPxPopupControl1" runat="server" HeaderText="Window 1"
            PopupElementID="ASPxButton1" PopupHorizontalAlign="LeftSides" PopupVerticalAlign="Below" CloseAction="CloseButton">
            <ContentCollection>
                <dxpc:PopupControlContentControl runat="server">
                    <dxe:ASPxButton ID="ASPxButton2" runat="server" Text="ASPxButton" AutoPostBack="False">
                    </dxe:ASPxButton>
                </dxpc:PopupControlContentControl>
            </ContentCollection>
        </dxpc:ASPxPopupControl>
        <dxpc:ASPxPopupControl ID="ASPxPopupControl2" runat="server" HeaderText="Window 2"
            PopupElementID="ASPxButton2" PopupHorizontalAlign="LeftSides" PopupVerticalAlign="Below" OnPopupElementResolve="ASPxPopupControl2_PopupElementResolve">
            <ContentCollection>
                <dxpc:PopupControlContentControl ID="PopupControlContentControl2" runat="server">
                    Hello
                </dxpc:PopupControlContentControl>
            </ContentCollection>
        </dxpc:ASPxPopupControl>

    protected void ASPxPopupControl2_PopupElementResolve(object sender, DevExpress.Web.ASPxClasses.ControlResolveEventArgs e) {
        if (e.ControlID == "ASPxButton2") {
            e.ResolvedControl = ASPxPopupControl1.FindControl(e.ControlID);
        }
    }

Thanks,
Andrew