Alert Dialog Kapatamıyorum

case R.id.duzenle:
         LayoutInflater layoutInflater= LayoutInflater.from(Cizelge.this);
                    View layout= layoutInflater.inflate(R.layout.guncelle,null);
                    final Spinner spinner2= (Spinner) layout.findViewById(R.id.spinner2);
                    final  EditText rakam2= (EditText) layout.findViewById(R.id.rakam2);
                    final  DatePicker datePicker2= (DatePicker) layout.findViewById(R.id.datePicker2);
                   final AlertDialog.Builder builder2= new AlertDialog.Builder(Cizelge.this);
                    builder2.setTitle("Güncelle");
                    builder2.setView(layout);
                    final AlertDialog alertDialog2=builder2.create();
                    Button kaydet2= (Button) layout.findViewById(R.id.kaydet2);
                    Button vazgec2= (Button) layout.findViewById(R.id.vazgec2);
                    builder2.show();
                    kaydet2.setOnClickListener(new View.OnClickListener() {
                        @Override
                        public void onClick(View v) {

                            int gun= datePicker2.getDayOfMonth();
                            int ay= datePicker2.getMonth() +1;
                            int yil= datePicker2.getYear();

                            DateFormat dateFormat2= new SimpleDateFormat("dd/MM/yyyy");
                            Date date2= null;
                            try {
                                date2=dateFormat2.parse(gun+"/"+ay+"/"+yil);
                            }catch (ParseException e){
                                e.printStackTrace();
                            }

                            long tarih= date2.getTime();
                            int pozisyon= spinner2.getSelectedItemPosition();
                            String ders= (String) spinner2.getItemAtPosition(pozisyon);
                            int sorusayisi= Integer.valueOf(rakam2.getText().toString());
                            Ogrenci ogrenci= new Ogrenci(ders, sorusayisi,tarih);
                            Veritabani db= new Veritabani(getApplicationContext());
                            db.Guncelle(id, tarih,ders,sorusayisi);
                            Listele();
                            alertDialog2.dismiss();
                        }
                    });