function ToggleAnswer(id) {
  var question = document.getElementById('q'+id);
  var answer   = document.getElementById('a'+id);
  if (question.className == 'hide') {
    question.className = 'show';
    answer.className   = 'show';
  } else {
    question.className = 'hide';
    answer.className   = 'hide';
  }
}