using (TextWriter writer = File.AppendText("filename.txt"))
writer.WriteLine("Firstname, {0} Lastname, {1} Phone,{2} Day of birth,{3} Month of Birth{4}", textBox1.Text, textBox2.Text,maskedTextBox1.Text, textBox4.Text, textB
for (int i = 0; i < dt.Rows.Count; i++) if (textBox1.Text == dt.Rows[i]["FIRSTNAME"].ToString()ss.Show(); } MessageBox.Show("UserName or Password is Wrong");
private void EnterValue_Click(object sender, EventArgs e) if (textBox1.Text !Regex.IsMatch(textBox1.Text, @"^[0-9]+$")) MessageBox.Show("Please only enter numberstextBox1.Clear();
//co