Is This Bug or i wrote a wrong code ?

[Hengky]

Hello i wanna ask about this ... 

i have a button with this code 

   Private Sub BtnBaru_Click(sender As System.Object, e As System.EventArgs) Handles BtnBaru.Click

       xStatus = "NEW"

        MCCBRekening.Enabled = True
        Isi_MCCBRekening()

        TxtKodeSubRekening.Enabled = True
    End Sub

 

and procedure Isi_MCCBRekening 

   Private Sub Isi_MCCBRekening()
        Dim TblMstRekening As DataTable

        TblMstRekening = ds.Tables.Add("Rekening")
        With TblMstRekening
            .Columns.Add("Kode", GetType(String))
            .Columns.Add("Nama", GetType(String))
        End With

        Using conn As New OleDbConnection(str)
            conn.Open()

            da = New OleDbDataAdapter("SELECT KodeRekening as Kode, NamaRekening as Nama FROM MstRekening ORDER BY KodeRekening", conn)
            ds = New DataSet
            ds.Clear()
            TblMstRekening.Rows.Add(New Object() {"", ""})

            da.Fill(TblMstRekening)
            da.Dispose()

            conn.Close()
        End Using

        With MCCBRekening
            .MultiColumnComboBoxElement.DropDownWidth = 500
            .DataSource = TblMstRekening
            .BestFitColumns()

            .EditorControl.EnableCustomFiltering = True

            .SelectedValue = ""
            .AutoFilter = True

            .DisplayMember = "Kode"
            .ValueMember = "Kode"
            .Text = ""

            Dim filter As New FilterDescriptor()
            filter.PropertyName = Me.MCCBRekening.ValueMember
            filter.[Operator] = FilterOperator.Contains
            Me.MCCBRekening.EditorControl.MasterTemplate.FilterDescriptors.Add(filter)
            MCCBRekening.MultiColumnComboBoxElement.EditorControl.EnableCustomFiltering = True

            AddHandler .MultiColumnComboBoxElement.EditorControl.CustomFiltering, AddressOf MCCBRekening_CustomFiltering
            AddHandler .KeyDown, AddressOf MCCBRekening_KeyDown

        End With
    End Sub
    Private Sub MCCBRekening_CustomFiltering(ByVal sender As Object, ByVal e As Telerik.WinControls.UI.GridViewCustomFilteringEventArgs)

        Dim element As RadMultiColumnComboBoxElement = MCCBRekening.MultiColumnComboBoxElement

        Dim textToSearch As String = MCCBRekening.Text
        If AutoCompleteMode.Append = (element.AutoCompleteMode And AutoCompleteMode.Append) Then
            If element.SelectionLength > 0 AndAlso element.SelectionStart > 0 Then
                textToSearch = MCCBRekening.Text.Substring(0, element.SelectionStart)
            End If
        End If

        If String.IsNullOrEmpty(textToSearch) Then
            e.Visible = True

            For i As Integer = 0 To element.EditorControl.ColumnCount - 1
                e.Row.Cells(i).Style.Reset()

            Next

            e.Row.InvalidateRow()
            Return
        End If

        e.Visible = False
        For i As Integer = 0 To element.EditorControl.ColumnCount - 1
            Dim text As String = e.Row.Cells(i).Value.ToString()
            If text.IndexOf(textToSearch, 0, StringComparison.InvariantCultureIgnoreCase) >= 0 Then
                e.Visible = True
                e.Row.Cells(i).Style.CustomizeFill = True
                e.Row.Cells(i).Style.DrawFill = True
                e.Row.Cells(i).Style.BackColor = Color.FromArgb(201, 252, 254)
            Else
                e.Row.Cells(i).Style.Reset()

            End If
        Next
        e.Row.InvalidateRow()
    End Sub
    Private Sub MCCBRekening_KeyDown(ByVal sender As Object, ByVal e As KeyEventArgs) Handles MCCBRekening.KeyDown
        With MCCBRekening
            If e.KeyCode = System.Windows.Forms.Keys.Enter Then
                If .ValueMember <> "" Then
                    .SelectedValue = .EditorControl.CurrentRow.Cells(.ValueMember).Value
                Else
                    .SelectedValue = .EditorControl.CurrentRow.Cells(.DisplayMember).Value
                End If

                .Text = .EditorControl.CurrentRow.Cells(.DisplayMember).Value.ToString()
                .MultiColumnComboBoxElement.ClosePopup()
                .MultiColumnComboBoxElement.TextBoxElement.TextBoxItem.SelectAll()
            End If
        End With
    End Sub
    Private Sub MCCBRekening_DropDownClosed(ByVal sender As Object, ByVal args As Telerik.WinControls.UI.RadPopupClosedEventArgs) Handles MCCBRekening.DropDownClosed
        If MCCBRekening.SelectedIndex <> -1 Then
            lblNamaRekening.Text = MCCBRekening.EditorControl.Rows(MCCBRekening.SelectedIndex).Cells(1).Value.ToString
            TxtKodeRekening.Text = MCCBRekening.EditorControl.Rows(MCCBRekening.SelectedIndex).Cells(0).Value.ToString
        Else
            TxtKodeRekening.Text = ""
            lblNamaRekening.Text = ""
        End If
    End Sub
    Private Sub MCCBRekening_Validated(ByVal sender As Object, ByVal e As System.EventArgs) Handles MCCBRekening.Validated
        If MCCBRekening.Text = "" Then
            TxtKodeRekening.Text = ""
            lblNamaRekening.Text = ""
        End If
    End Sub

my question is :

why if i click the button for the second time it's give me error message ... the "Kode" is not belong to TblMstRekening .... 

 

how i  fix this thanks ...