I get document is not defined error

// event listener to respond to "Show another quote" button clicks
// when user clicks anywhere on the button, the "printQuote" function is called
var button = document.getElementById('loadQuote');
button.addEventListener("click", printQuote, false);





//First i make the varible random have a random number between 0 - 5
function getRandomQuote(quotes) {
    var random = Math.floor((Math.random() * quotes.length) );
    return quotes[random];


}

function printQuote() {
    var red = Math.floor(Math.random() * 256);
    var green = Math.floor(Math.random() * 256);
    var blue = Math.floor(Math.random() * 256);

    var ranrgb= "rgb("+ red + "," + green + "," + blue + ")";
    style.backgroundColor = ranrgb;

    var randomQuote = getRandomQuote(quotes);
    var html = '<p class ="quote">' + randomQuote.quote + "</p>" + '<p class = "source">' + randomQuote.source + "</p>";
    document.getElementById('quote-box').innerHTML = html;
}

//Here is a array of objects that stores qoutes and the source 

var quotes = [
    {
        quote: "But man is not made for defeat. A man can be destroyed but not defeated",
        source: "Ernest Hemingway"
    },
    {
        quote: "All that we see or seem is but a dream within a dream",
        source: "Edgar Allan Poe"
    },
    {
        quote: "There is no charm equal to tenderness of heart",
        source: "Jane Austen"
    },
    {
        quote: "Learning never exhausts the mind",
        source: "Leonardo da Vinci"
    },
    {
        quote: "If you cannot do great things, do small things in a great way",
        source: "Napoleon Hill"
    }
];