Trigger JQuery function when passed half way down the page
<p>Is there a way to tell if you have scrolled passed the center of the web page or in other words, when you have scrolled passed exactly half of the web page and your scrollbar is situated in the lower half of the browser window? </p>

<p>I want to be able to trigger this: 
$('.pineapple-man').show(); when I have scrolled down passed half of the page?</p>

<p>Is this possible at all?</p>

<p>Your help would be so kind!  </p>
