Bootstrap carousel slide function. Things won't work in Mozilla

by ringstaff

HTML

<link rel="stylesheet" href="//netdna.bootstrapcdn.com/bootstrap/3.0.2/css/bootstrap.min.css">
<script src="//netdna.bootstrapcdn.com/bootstrap/3.0.2/js/bootstrap.min.js"></script>
<div id="carousel-showcase" class="carousel slide" data-ride="carousel">
    <!-- Indicators -->
    <ol class="carousel-indicators">
        <li data-target="#myCarousel" data-slide-to="0" class="active"></li>
        <li data-target="#myCarousel" data-slide-to="1" class=""></li>
        <li data-target="#myCarousel" data-slide-to="2" class=""></li>
    </ol>
    <div class="carousel-inner">
        <div class="item active">
            <div class="container">
                <div class="carousel-caption">
                     <h1>Example headline.</h1>
                    <p><a class="btn btn-lg btn-primary" href="#" role="button">Sign up today</a></p>
                </div>
            </div>
        </div>
        <div class="item">
            <div class="container">
                <div class="carousel-caption">
                     <h1>Another example headline.</h1>
                    <p><a class="btn btn-lg btn-primary" href="#" role="button">Learn more</a></p>
                </div>
            </div>
        </div>
        <div class="item">
            <div class="container">
                <div class="carousel-caption">
                     <h1>One more for good measure.</h1>
                    <p><a class="btn btn-lg btn-primary" href="#" role="button">Browse gallery</a></p>
                </div>
            </div>
        </div>
    </div> <a class="left carousel-control" href="#carousel-showcase" data-slide="prev"><span class="glyphicon glyphicon-chevron-left"></span></a>
 <a class="right carousel-control" href="#carousel-showcase" data-slide="next"><span class="glyphicon glyphicon-chevron-right"></span></a>

</div>

<div id="wrap"></div>

CSS

.item {
    height: 300px;
}

#wrap {
    width: 200px;
    height: 150px;
    background: url(http://placehold.it/350x150);
}

JavaScript

var $carousel = $('#carousel-showcase');
$carousel.carousel();
var positionX = 0;
$carousel.bind('slide.bs.carousel', function (e) {

  setTimeout( function(){
    var left = $carousel.find('.item.active.left');
    var right = $carousel.find('.item.active.right');
    if(left.length > 0) {
        positionX += 50;
        $("#wrap").css('backgroundPosition', ["",positionX,'% 0%'].join(""));
    }
    else if(right.length > 0) {
        positionX -= 50;
        $("#wrap").css('backgroundPosition',["",positionX,'% 0%'].join(""));
    }
  }, 500);
});