private void BtnSubmit_Click(object sender, RoutedEventArgs e)
        {
            string input;
            input = txtAcc.Text;

            if (currentName == "")
            {
                currentName = input;
                tbOutput.Text = currentName;
            }

            else

                currentName = currentName + "\r\n" + input;

            tbOutput.Text = currentName;
        }