modal popup does not show up due to validation summary which is outside the modal popup

Hi

I hava a modal pop up which opens up from code behind, it is giving javascript error due to validation summary which is out side the popup

the button wich opens up the pop up is set with CausesValidation="false" and i have also specified

ValidationGroup in ValidationSummary

<asp:ValidationSummary ID="vldSummaryMain" runat="server" ValidationGroup="Input" />

<asp:ImageButton ID="ImageButton2" runat="server" Style="display: none;" CausesValidation="false"></asp:ImageButton><ajaxToolkit:ModalPopupExtender ID="ModalPopupForCalculation" runat="server" TargetControlID="ImageButton2"
        PopupControlID="pnlCalculationSummary" DropShadow="false" CancelControlID="lnkBtnCancelCalc"
        BackgroundCssClass="modalBackground" />

<asp:LinkButton ID="lbkbtnCalculatePostageStatement" class="button" runat="server"
                                OnClick="lbkbtnCalculatePostageStatement_Click" CausesValidation="false">Show Popup</asp:LinkButton>

<asp:Panel ID="pnlCalculationSummary" runat="server" Style="display: none;"><asp:LinkButton ID="lnkBtnCancelCalc" runat="server" class="button" CausesValidation="false">Cancel</asp:LinkButton>&nbsp;</asp:Panel>

Show Popup button shows the popup from code behind


plz help
thanks