Radconfirm when deleting a recurrence appointment

[Jully]

Hello,
    When deleting a recurrence appointment, I want to pop up another confirmation dialog before pop up the original delete confirmation dialog using OnClientAppointmentDeleting event.

<telerik:RadScheduler  ID="uxTimeOfDayRadScheduler" ..  

OnClientRecurrenceActionDialogShowing="uxTimeOfDayRadScheduler_OnClientRecurrenceActionDialogShowing">

function uxTimeOfDayRadScheduler_OnClientRecurrenceActionDialogShowing(sender, eventArgs){


    if (eventArgs.get_recurrenceAction() == 2) {

    eventArgs.set_cancel(true);    
    //Pop  a confirmation window     
    var confirmMessage =  "Deleting this appointment may affect other scripts. Do you want to delete this appointment?";     
    radconfirm(confirmMessage, 
        function (arg) {   
            if (arg){      
            eventArgs.set_cancel(false);
            }
        },330, 100, null, 'Delete Appointment');

    }
}

But, when on the OnClientAppointmentDeleting event, I put a radconfirm, it doesn't wait for an answer from the client and pop up the original delete confirmation dialog before I could choose.

I tried to call set_cancel(true) before calling my own radconfirm, but if I call set_cancel(false) after clicked 'ok' in my own radconfirm, it doesn't pop up the original delete confirmation dialog. Can anyone Help ?


Thanks