Visual Basic - Guardar los archivos de en textbox al volver a ejecutar el programa

Public filename As String

Private Sub Form_Load()

'aqui leo los valores

Dim textoleido As String

filename = App.Path & "\x.txt"

Open filename For Input As 1

  While Not EOF(1)

        Line Input #1, textoleido

        Text1.Text = textoleido

    Wend

  Close 1

End Sub

Private Sub Form_Unload(Cancel As Integer)

'aqui grabo los valores al cerrar

Kill filename

Open filename For Append As 1

    Print #1, Text1.Text

Close 1

End Sub