JavaScript图像滑块不工作

它只停留在一张图像上，不会推进幻灯片。我检查了其他有相同代码的帖子，没有发现任何差异。我需要它都是一个单一的html，因为我正在使用这个Wordpress。

这是我的html代码：

<style>
#slideshow { 
    position: relative; 
    width: 240px; 
    height: 240px; 
    padding: 10px; 
    box-shadow: 0 0 20px rgba(0,0,0,0.4); 
}
#slideshow > div {  
    position: absolute;
    top: 10px; 
    left: 10px; 
    right: 10px; 
    bottom: 10px; 
}
</style>
<div id="slideshow">
<div>
<a href="http://www.slideshare.net/billbayer/sell-or-die-the-sales-imperative">
<img src="http://www.billbayer.net/wp-content/uploads/2013/08/sell.png" width="100%" height="100%">
</a>
</div>
<div>
<a href="http://www.slideshare.net/billbayer/bill-bayer-2013-economic-forecast">
<img src="http://www.billbayer.net/wp-content/uploads/2013/08/economic.png" width="100%" height="100%">
</a>
</div>
<div>
<a href="http://www.slideshare.net/billbayer/lgr-fatal-illusions-april-2009">
<img src="http://www.billbayer.net/wp-content/uploads/2013/08/fatal.png" width="100%" height="100%">
</a>
</div>
<div>
<a href="http://www.slideshare.net/billbayer/mastering-change-march-21-2013">
<img src="http://www.billbayer.net/wp-content/uploads/2013/08/mastering.png" width="100%" height="100%">
</a>
</div>
</div>
<script>
$("#slideshow > div:gt(0)").hide();
setInterval(function() { 
  $('#slideshow > div:first')
    .fadeOut(1000)
    .next()
    .fadeIn(1000)
    .end()
    .appendTo('#slideshow');
},  3000);
</script>

http://jsfiddle.net/Rouse94/j6PSA/