Ajax日历扩展器可以有Boundfield作为TargetControlID

Ajax CalendarExtender可以有asp:BoundField作为TragetControlID，因为在网格中我有，它说不可用。我怎么能得到每个日期从日历到BoundField?

<asp:TemplateField ItemStyle-HorizontalAlign="center" ItemStyle-VerticalAlign="Middle" FooterStyle-Width="25px" HeaderText="Schedule">
                <ItemTemplate>
         <asp:ImageButton ID="CalendarIcon" runat="server" ImageUrl="~/images/calender-no-edit.gif" />&nbsp;
               <ajaxToolkit:CalendarExtender ID="CalendarExtender1" runat="server" PopupPosition="Left" PopupButtonID="CalendarIcon"
                    TargetControlID="ScheduleDate" >
                </ajaxToolkit:CalendarExtender>
                </ItemTemplate>
            </asp:TemplateField>
                <asp:BoundField DataField="ScheduleDate" HeaderText="Deal"><HeaderStyle HorizontalAlign="Left" /></asp:BoundField>

谢谢,