quiz challenge

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 html;

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

}

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

html = "You got " + correctAnswers + " question(s) right.";
print(html);