private void metroTextBox10_TextChanged(object sender, EventArgs e) { string nationality = metroTextBox10.Text; if (ValidateExam.isLetter(nationality)) { errorProvider4.SetError(metroTextBox10, "Can contain only letters"); } else { errorProvider4.Clear(); } }
private void metroTextBox3_TextChanged(object sender, EventArgs e) { string lname = metroTextBox3.Text; if (ValidateExam.isLetter(lname)) { errorProvider3.SetError(metroTextBox3, "Can contain only letters"); } else { errorProvider3.Clear(); } }