Can't figure out why this isn't working, JS console say fail on line 1 ???? Help!

var questions = [
  ['How many states are in the United States?', 50],
  ['How many continents are there?', 7],
  ['How many legs does an insect have?', 6]
];

var correctAnswers = 0;
var question;
var answer;
var response;

var correct = [ ];
var wrong = [ ];

function print(message) {
  var outputDiv = document.getElementById('output');
  outputDiv.innerHTML = message;
}

function buildList(arr) {
  var listHTML = '<ol>';
  for (var i = 0; i < arr.length; i += 1) {
    listHTML += '<li>' + arr[i] + '</li>';
  }
  listHTML += '</ol>';
  return listHTML;
}


for (var i = 0; i < questions.length; i += 1) {
  question = questions[i][0];
  answer = questions[i][1];
  response = prompt(question);
  response = parseInt(response);
  if (response === answer) {
    correctAnswers += 1;
    correct.push(question);
  } else {
    wrong.push(question);
}

var html = "You got " + correctAnswers + " question(s) right.";
html += "<h2>The answer you got right were:</h2>"
html += buidList(correct);
html += buildList(wrong);
print(html);