mscorlib object reference not set to an instance of an object

[ShwetaJain]

Hi i m getting error "mscorlib object reference not set to an instance of an object" in my programming when i am trying to retrieve the sender name or recipient name from folders in MAPI with exchange server.

Here is the code:

Public Sub Read_TasksRequest(ByVal oMsgColl As MAPI.Messages)
        ' Dim oMsgColl As MAPI.Messages
        Dim oMsgFilter As MAPI.MessageFilter
        Console.WriteLine("-----------------------------")
        Console.WriteLine("Tasks Request")
        Console.WriteLine("----------------------------")
        ' oMsgColl = ObjFolder.Messages
        oMsgFilter = oMsgColl.Filter
        oMsgFilter.Type = TaskRequestType
        Dim iTsks As MAPI.Message
        iTsks = oMsgColl.GetFirst
        Do While (Not iTsks Is Nothing)
            'If iTsks.Unread = True Then
            '    Console.WriteLine("Message is read")
            'Else
            '    Console.WriteLine("Message is unread")
            'End If
            Console.WriteLine(iTsks.Text)
            Console.WriteLine(iTsks.Subject)
            Console.WriteLine(iTsks.ID)
            Dim sender1 As Object
            If iTsks.Sent = True Then
                sender1 = iTsks.Sender
                Dim strSender As String = sender1.Name
                If Not strSender = "" Then
                    Console.WriteLine(strSender)
                End If
                'display_sender(sender)
            End If
            sender1 = Nothing
            'End If
            iTsks = oMsgColl.GetNext
        Loop
        oMsgColl = Nothing
        oMsgFilter = Nothing
        iTsks = Nothing
        Console.WriteLine("-----------------------------")
        Console.WriteLine("End Task Request")
        Console.WriteLine("----------------------------")

    End Sub

[tlhintoq]

Where did Visual Studio stop? What line did it break on?