button inside modalpopup doesn't fire the event

Question

hi,

i've a simple search form with two textfield and on button. the result is displayed in gridview. All this is inside a modalpopup. the content of the modalpopup (the controls) are in the same page (parent page). i am not using iframe and updatepanel. the problem i've now is: when i click on the search button (btnFind), the event doesn't fire.

can some help me, or give me an appropriate advice.

thnx in advance.

<ajaxToolkit:ModalPopupExtender ID="ModalPopupExtender1" runat="server" CancelControlID="btnCancel"
    OkControlID="btnOkay" TargetControlID="Button1" PopupControlID="Panel1" PopupDragHandleControlID="PopupHeader"
    Drag="true" BackgroundCssClass="ModalPopupBG">
</ajaxToolkit:ModalPopupExtender>
<asp:Panel ID="Panel1" CssClass="popupConfirmation" runat="server">
    <div class="popup_Container">
        <div class="popup_Titlebar">
            <div class="TitlebarLeft">
                Find Administration</div>
        </div>
        <div class="popup_Body">
            <div class="tabela" style="overflow: auto">
                <table cellspacing="10px">
                    <tr>
                        <td>
                            <asp:Label ID="lblName" runat="server" Text="Name" CssClass="inputText"></asp:Label>
                        </td>
                        <td>
                            <asp:TextBox ID="txtName" runat="server" CssClass="textbox"></asp:TextBox>
                        </td>
                        <td>
                            <asp:Button ID="btnFind" runat="server" Text="Find" CssClass="button" />
                        </td>
                    </tr>
                </table>
            </div>
            <div class="tabela" style="overflow: auto">
                <asp:GridView ID="gvAdministration" runat="server" AutoGenerateColumns="False" CssClass="table"
                    DataKeyNames="Id">
                    <RowStyle CssClass="gridviewRow" />
                    <HeaderStyle CssClass="gridviewHeader" />
                    <AlternatingRowStyle CssClass="gridviewRowAlt" />
                    <Columns>
                        <asp:BoundField DataField="Id" HeaderText="Id" SortExpression="Id" />                            
                        <asp:CommandField ShowSelectButton="True" />
                    </Columns>
                    <HeaderStyle CssClass="gridviewHeader" />
                </asp:GridView>
            </div>
        </div>
        <div class="popup_Buttons">
            <asp:Button ID="btnOkay" Text="Done" runat="server" />
            <asp:Button ID="btnCancel" Text="Cancel" runat="server" />
        </div>
    </div>
</asp:Panel>