Android Question not save txt, whi?

Sub Timer1_Tick
    If connected Then
       
        If TextReader1.Ready Then 'check if there is any data waiting to be read
            txtLog.Text = txtLog.Text & TextReader1.ReadLine & CRLF
            txtLog.SelectionStart = txtLog.Text.Length
            txtdisplay.Text=txtLog.Text
           
           
            Dim k As Int
            k = txtLog.Text.IndexOf("id ")' eseguo la ricerca di Tavolo: per poter estrapolare solo la cifra da inserire nella txteuro.text ' this modify with id replaced with Tavolo: 
            If k >= 0 Then
                txttavolo.Text = txtLog.Text.SubString2(k + 2, txtLog.Text.Length)' da qui estrapolo il tavolo
               
               
                End If
            End If
    End If
   
   
   
End Sub

Sub btnprint_Click
    mp1.Load(File.DirAssets,"click.wav")
    mp1.Play
    DateTime.DateFormat="dd/MM/yyyy"
    DateTime.TimeFormat="HH.mm"
    If txteuroparziale.Text="" Then
    Else
    End If
       
    If connected Then
       
        btncalcola_Click
        contatore= contatore +1
        txtcontatore.Text=contatore
       
        TextWriter1.WriteLine("COMANDA" & " Numero: " & txtcontatore.Text & " - " & DateTime.Date (now) & " - ORE:" &  DateTime.Time (now) & CRLF)
        TextWriter1.WriteLine("Operatore: " & txtoperatore.Text &  " - Tavolo: " & txttavolo.Text & CRLF)
        TextWriter1.WriteLine(" " & lblm1.Text & " " &  CRLF)
        For i = 0 To lswordine2.Size -1
            TextWriter1.WriteLine(lswordine2.GetItem(i) & CRLF)
           
           
        Next
        TextWriter1.WriteLine("                            " & CRLF)
        TextWriter1.WriteLine("===========================" & CRLF)
        TextWriter1.WriteLine("                            " & CRLF)
        TextWriter1.WriteLine("COMANDA" & " Numero: " & txtcontatore.Text & " - " & DateTime.Date (now) & " - ORE:" &  DateTime.Time (now) & CRLF)
        TextWriter1.WriteLine("Operatore: " & txtoperatore.Text &  " - Tavolo: " & txttavolo.Text & CRLF)
        TextWriter1.WriteLine(" " & lblm2.Text & " " & CRLF)
        For i = 0 To lswordine.Size -1
            TextWriter1.WriteLine(lswordine.GetItem(i) & CRLF)
           
        Next
        TextWriter1.WriteLine(" Note: " & txtnote.Text & CRLF)
        TextWriter1.WriteLine("TOTALE EURO: " & txttotaleeuro.Text   & CRLF)
        TextWriter1.WriteLine("id " & txttavolo.Text & CRLF) ' this code added after modify, before substring index ("TAvolo:")  now substring ("id ") 
        TextWriter1.WriteLine("                    ")
        TextWriter1.WriteLine("                    ")
        TextWriter1.WriteLine("                    ")
        TextWriter1.Flush
            
 

        End If
            mnuDisconnect_Click
        Msgbox("Comanda inviata","ESEGUITO")
       
    Else
        mp1.Load(File.DirAssets,"alert.wav")
        mp1.Play
        Msgbox("Attenzione connetti la stampante","STAMPANTE NON CONNESSA")
    End If

  

   
End Sub