update "DeleteDate" field when deleting event

I would like to update the “DeleteDate” field from the server-side when user delete an event.
How can i update the specified field when the user delete an normal event and recurring event?

// Save.ashx

[code]Imports System.Web
Imports System.Web.Services

Imports DHTMLX.Common

Public Class Save
Implements System.Web.IHttpHandler

Protected Function deleteRelated(ByVal action As DataAction, ByVal changedEvent As Events_Tran, ByVal context As SchedulerDataContext) As Boolean
    Dim finished As Boolean = False

    If (action.Type = DataActionTypes.Delete OrElse action.Type = DataActionTypes.Update) AndAlso Not String.IsNullOrEmpty(changedEvent.rec_type) Then
        context.Events_Trans.DeleteAllOnSubmit(From ev In context.Events_Trans Where ev.event_pid = changedEvent.id)
    End If

    If action.Type = DataActionTypes.Delete AndAlso changedEvent.event_pid <> 0 Then
        Dim changed As Events_Tran = (From ev In context.Events_Trans Where ev.id = action.TargetId).[Single]()
        changed.rec_type = "none"
        finished = True
    End If

    Return finished
End Function

Protected Function insertRelated(ByVal action As DataAction, ByVal changedEvent As Events_Tran, ByVal context As SchedulerDataContext) As DataAction
    If action.Type = DataActionTypes.Insert AndAlso changedEvent.rec_type = "none" Then
        action.Type = DataActionTypes.Delete
    End If
    Return action
End Function

Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest
    context.Response.ContentType = "text/xml"
    Dim action = New DataAction(context.Request.Form)
    Dim data = New SchedulerDataContext()
    'Dim result = New AjaxSaveResponse(data)

        Dim changedEvent = DirectCast(DHXEventsHelper.Bind(GetType(Events_Tran), context.Request.Form), Events_Tran)
        Dim isFinished As Boolean = deleteRelated(action, changedEvent, data)
        If Not isFinished Then
            Select Case action.Type
                Case DataActionTypes.Insert
                    ' define here your Insert logic
                    'result.UpdateField("CreDt", DateTime.Now)

                    Exit Select
                Case DataActionTypes.Delete
                    ' define here your Delete logic
                    changedEvent = data.Events_Trans.SingleOrDefault(Function(ev) ev.id = action.SourceId)

                    Exit Select
                Case Else
                    ' "update" // define here your Update logic
                    Dim updated = data.Events_Trans.SingleOrDefault(Function(ev) ev.id = action.SourceId)
                    DHXEventsHelper.Update(updated, changedEvent, New List(Of String)() From {"id"})

                    Exit Select
            End Select
        End If
        action.TargetId = changedEvent.id
        action = insertRelated(action, changedEvent, data)
    Catch a As Exception
        action.Type = DataActionTypes.[Error]
    End Try

    context.Response.Write(New AjaxSaveResponse(action).ToString())
End Sub

ReadOnly Property IsReusable() As Boolean Implements IHttpHandler.IsReusable
        Return False
    End Get
End Property

End Class[/code]