Removing attachments from Purchase Order using DIAPI

Dear all,

I have added attachment to PO using DIAPI. I have given below the code.

           Dim oAtt As SAPbobsCOM.Attachments2 = oCompany.GetBusinessObject(SAPbobsCOM.BoObjectTypes.oAttachments2)
            Dim FileName As String = ""
            Dim SourceFile As String = ""
            Dim DestinationFile As String = ""

            For i As Integer = 0 To PurchaseOrderInfo.Attachments.Length - 1

                FileName = PurchaseOrderInfo.Attachments(i).FileName
                SourceFile = PurchaseOrderInfo.Attachments(i).SourcePath & "\" & FileName
                DestinationFile = PurchaseOrderInfo.Attachments(i).TargetPath & "\" & FileName

           
                If i > 0 Then oAtt.Lines.Add()
                oAtt.Lines.SetCurrentLine(i)
                oAtt.Lines.FileName = System.IO.Path.GetFileNameWithoutExtension(FileName)
                oAtt.Lines.FileExtension = Replace(System.IO.Path.GetExtension(FileName), ".", "")
                oAtt.Lines.SourcePath = PurchaseOrderInfo.Attachments(i).SourcePath

                If System.IO.File.Exists(DestinationFile) Then
                    System.IO.File.Delete(DestinationFile)
                End If

                If PurchaseOrderInfo.Attachments(i).Override = True Then
                    oAtt.Lines.Override = SAPbobsCOM.BoYesNoEnum.tYES
                Else
                    oAtt.Lines.Override = SAPbobsCOM.BoYesNoEnum.tNO
                End If

            Next

            Dim iAttEntry As Integer = -1
            Dim lResult As Long
            Dim lErrCode As Long, sErrMsg As String = ""

            lResult = oAtt.Add()

         It works fine. But, I am not  able to remove an attachment via diapi.

         Could you please help me how to solve this.

Thanks in advance.

Manikandan