Random Quote Generator - request to help with code.

// event listener to respond to "Show another quote" button clicks
// when user clicks anywhere on the button, the "printQuote" function is called
document.getElementById('loadQuote').addEventListener("click", printQuote, false);
var randomNumber;
var quoteObject;
var printedText;
var quotes = [
    {quote: "The coldest  winter I ever spent was a summer in San Fransisco.", source: "Mark Twain"},
    {quote: "You can do anyting, but not everything.", source: "Woody Allen"},
    {quote: "Those who dare to fail miserably can achive greatly.", source: "John F. Kennedy"},
    {quote: "The true sign of intelligence is not knowledge but imagination.", source: "Albert Einstein"}
];

function getRandomQuote(){
    randomNumber = Math.floor(Math.random()*quotes.length); //selects a random quote object from the quotes array
    return quotes[randomNumber];//returns the randomly selected quote object
};

function printQuote(){
    quoteObject = getRandomQuote(); //calls the getRandomQuote function and stores the returned quote object in a variable
    printedText = "<p class=\"quote\">" + quoteObject.quote + "</p><p class=\"source\"> " + quoteObject.source + "</p>"; //html text
    document.getElementById('quote-box').innerHTML = printedText; //print onto page
};