RegularExpressionValidator and the new AsyncFileUpload

 Hi,

I try to valide the new AJAX AsyncFileUpload control but it seems not to work : Control 'AsyncFileUpload1' referenced by the ControlToValidate property of 'REV1' cannot be validated.

<cc1:AsyncFileUpload ID="AsyncFileUpload1" runat="server" Width="400px"
                    ThrobberID="throbber" />
                <asp:Label ID="throbber" Style="display: none" runat="server"><img alt="loading" src="images/upload.gif" /></asp:Label><asp:RegularExpressionValidator
                    ID="REV1" runat="server" ErrorMessage=" ...