Detect when Facebook loads extra pages

First off, i'm new to programming/javascript. I'm trying to detect when facebook loads new pages if you scroll down to the bottom of a page or a timeline page. And then when it has detected that I want to run a JS script. I've looked in the source-code of facebook and I've found this:

<a class="pam uiBoxLightblue uiMorePagerPrimary" onclick="(JSCC.get(&quot;ji9EntmPx4Hav1HbcgX0&quot;) &amp;&amp; JSCC.get(&quot;ji9EntmPx4Hav1HbcgX0&quot;).getHandler())(); return false;" href="#" role="button">See More Stories</a>

How would I go about and detect when Facebook loads in new pages?

Thanks in advance!