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using (StreamReader sr = new StreamReader("SF.txt"))
                {
                    string load;
                    TextReader tr = new StreamReader("SF.txt");
                    load = (tr.ReadLine());
                   

                    string CurLine = "";
                    if (String.IsNullOrEmpty(CurLine = tr.ReadLine()))
                    {
                        using (StreamWriter sw = new StreamWriter("SF.txt"))
                        {
                            sw.WriteLine(textBox1.Text);

                            Form2 form2 = new Form2();
                            form2.Show();
                            Hide();
                        }
                    }
                }