Favourite randomiser

<a id="fav" href="#">Favourite</a>

<script>
function shuffleArray(array) {
    for (var i = array.length - 1; i > 0; i--) {
        var j = Math.floor(Math.random() * (i + 1));
        var temp = array[i];
        array[i] = array[j];
        array[j] = temp;
    }
    return array;
}

fav = shuffleArray(["url-1", "url-2"]);

$("#fav").attr("href", "http://" + fav[1] + ".tumblr.com");
</script>