var quiz = new Array(1,2);
function select(q,a) {
  var aId = document.getElementById('a'+q);
  if (aId) {
    aId.style.display='block';
  }
}
function next(q) {
  var question = document.getElementById('q'+q);
  if (question) {
    question.style.display='list-item';
  }
  question = document.getElementById('q'+(q-1));
  if (question) {
    question.style.display='none';
  }
}