private void SubmitBtn_Click(object sender, RoutedEventArgs e) { try { if (usernameTxt.Text.Length == 0) { errormessage.Text = "Enter a username."; usernameTxt.Focus(); } else { string username = usernameTxt.Text; string password = passwordBox.Password; if (passwordBox.Password.Length == 0) { errormessage.Text = "Enter password."; passwordBox.Focus(); } else if (passwordBoxConfirm.Password.Length == 0) { errormessage.Text = "Enter the Confirm password."; passwordBoxConfirm.Focus(); } else if (passwordBox.Password != passwordBoxConfirm.Password) { errormessage.Text = "Confirm password must be same as password."; passwordBoxConfirm.Focus(); } else { errormessage.Text = string.Empty; //check if username already exists. Go back to login. string savedUsername; byte[] ciphertext; byte[] entropy; if (PasswordUtility.RetrievePasswordFromRegistry(out savedUsername, out ciphertext, out entropy)) { errormessage.Text = "The software is already registered to a user. " + "Please login with the username and password used to register the software."; Reset(); } else { PasswordUtility.Encrypt(passwordBox.Password, out ciphertext, out entropy); PasswordUtility.StorePasswordInRegistry(username, ciphertext, entropy); DatabaseInfo.SetPassword(passwordBox.Password); errormessage.Text = "You have registered successfully."; Reset(); mainWindow = new MainWindow(); mainWindow.Show(); Close(); } } } } catch (Exception ex) { MessageBox.Show(ex.Message + ex.StackTrace); } }