private void comboBoxName_SelectedIndexChanged(object sender, EventArgs e) { checkBoxDefaultSignature.Checked = false; string sqlQuery = "SELECT signature FROM user WHERE name ='" + comboBoxName.Text + "'"; // Put infos in textboxes connectionDB.PutQueryIntoTextBox(sqlQuery, textBoxSignature, "signature"); sqlQuery = "SELECT id FROM user WHERE name = '" + comboBoxName.Text + "'"; idUser = connectionDB.getUserId(comboBoxName.Text); // Get the id of the user (in order to update later) if (comboBoxName.Text == Properties.Settings.Default.Signature) { checkBoxDefaultSignature.Checked = true; } }