Schedular Edit series

[pich cock]

I bind the schedular with objectdatasource...inseting and update with that datasource only......when i edit the 0ccurence it works and when i edit with series it getting some error like object reference is not set to be istance of class ..i think  some value is not passing... i written
like this
below
 <telerik:RadScheduler ID="RadScheduler1" runat="server" Skin="Web20" DataSourceID="ods_calender"
         DataKeyField="calendartaskid" DataSubjectField="description" DataStartField="startdate"
        DataEndField="enddate" DataRecurrenceField="recurrencerule" DataRecurrenceParentKeyField="recurrenceruleid"
        OnAppointmentDelete="RadScheduler1_AppointmentDelete" OnAppointmentClick="RadScheduler1_AppointmentClick"
        OnOccurrenceDelete="RadScheduler1_OccurrenceDelete">
     
    </telerik:RadScheduler>
    <asp:ObjectDataSource ID="ods_calender" runat="server" InsertMethod="insertUpdate_Calendertasks"
        SelectMethod="Get_Calendertasks" TypeName="General" UpdateMethod="insertUpdate_Calendertasks"
        DeleteMethod="insertUpdate_Calendertasks">
        <%-- <DeleteParameters>
            <asp:Parameter Name="calendartaskid" Type="Int32" />
            <asp:Parameter Name="description" Type="String" />
            <asp:Parameter Name="startdate" Type="DateTime" />
            <asp:Parameter Name="enddate" Type="DateTime" />
            <asp:Parameter Name="recurrencerule" Type="String" />
            <asp:Parameter Name="recurrenceruleid" Type="Int32" />
            <asp:Parameter Name="Recordtype" Type="String" />
            <asp:SessionParameter Name="doneby" Type="Int32" SessionField="UserID" />
            <asp:Parameter Name="cmd" Type="String" DefaultValue="D" />
        </DeleteParameters>--%>
        <UpdateParameters>
           <%-- <asp:ControlParameter ControlID="hdn_appid" Type="Int32" Name="calendartaskid" />--%>
            <asp:Parameter Name="calendartaskid" Type="Int32" />
            <asp:Parameter Name="description" Type="String" />
            <asp:Parameter Name="startdate" Type="DateTime" />
            <asp:Parameter Name="enddate" Type="DateTime" />
            <asp:Parameter Name="recurrencerule" Type="String" />
            <asp:Parameter Name="recurrenceruleid" Type="Int32" />
            <asp:Parameter Name="Recordtype" Type="String" DefaultValue="C" />
            <asp:SessionParameter Name="doneby" Type="Int32" SessionField="UserID" />
            <asp:Parameter Name="cmd" Type="String" DefaultValue="M" />
        </UpdateParameters>
        <InsertParameters>
            <asp:Parameter Name="calendartaskid" Type="Int32" DefaultValue="0" />
            <asp:Parameter Name="description" Type="String" />
            <asp:Parameter Name="startdate" Type="DateTime" />
            <asp:Parameter Name="enddate" Type="DateTime" />
            <asp:Parameter Name="recurrencerule" Type="String" />
            <asp:Parameter Name="recurrenceruleid" Type="Int32" />
            <asp:Parameter Name="Recordtype" Type="String" DefaultValue="C" />
            <asp:SessionParameter Name="doneby" Type="Int32" SessionField="UserID" />
            <asp:Parameter Name="cmd" Type="String" DefaultValue="C" />
        </InsertParameters>
    </asp:ObjectDataSource>



no coding part only source  can u rectify the  error