Javascript Konami Code

if (window.addEventListener) {
    keys = [], code = [38, 38, 40, 40, 37, 39, 37, 39, 66, 65];

    window.addEventListener("keyup", function(e) {
        keys.push(e.keyCode);
        if (keys.length > code.length) {
            keys.shift();
        }

        if (keys.length == code.length) {
            if (keys.toString() == code.toString()) {
                console.log("you did it!");
            }
        }
    });
}