RadGrid And AddNewRecord(New Action By Me) Problem In Ajaxify Mode

Question

hi my dear friends:

i ajaxified my RadGrid like this :

                        <telerik:RadAjaxManager ID="RadAjaxManager1" runat="server"> 
                            <AjaxSettings> 
                                <telerik:AjaxSetting AjaxControlID="grdPersonel"> 
                                    <UpdatedControls> 
                                        <telerik:AjaxUpdatedControl ControlID="grdPersonel"  
                                            LoadingPanelID="RadAjaxLoadingPanel1" /> 
                                    </UpdatedControls> 
                                </telerik:AjaxSetting> 
                            </AjaxSettings> 
                        </telerik:RadAjaxManager> 
                        <telerik:RadAjaxLoadingPanel ID="RadAjaxLoadingPanel1" runat="server" />

i am controling Radgrid AddNewRecord By Myself like this :

    protected void grdPersonel_ItemCommand(object source, Telerik.Web.UI.GridCommandEventArgs e) 
    { 
        switch (e.CommandName) 
        { 
            case RadGrid.InitInsertCommandName: 
                { 
                    e.Canceled = true; 
                    hfEditMode.Value = "Insert"; 
                    ResetForm(); 
                    mvPersonel.SetActiveView(vwPersonelEdit); 
                    break; 
                } 
        } 
    } 

i have some views in my multyview (mvPersonel):

View1 (vwForGird)-> my grid is here.

View2 (vwPersonelEdit)-> I have A table here (with some textboxes and some lables and a save button)for add a new record in grid.

when u press addnewrecord in grid so i reset all of the textboxes in View2 (vwPersonelEdit) and jump to it.

that upper code was working prefectly until i ajaxified my radgrid like upper code.

when i press addnewrecord i recieve this error :

Line: 6 Error: Sys.WebForms.PageRequestManagerServerErrorException: Object reference not set to an instance of an object.

i really really wondering how can i solve this problem ?

how can i force addnewrecord in radgrid to postback after click on it not callback...