Before, after photos: Javascript

gistfile1.txt

<script src="http://code.jquery.com/jquery-latest.min.js" type="text/javascript"></script>
<script type="text/javascript" language="JavaScript">
$(document).ready(function() {
  $('.trackMe').each(function(){
		$(this).children("img:last").mousemove(function(e) {
			var offset = $(this).offset();
			var xpos = (e.pageX - offset.left);
   			var ypos = (e.pageY - offset.top);
			//now to get the first child image width..
			var thisImage = $(this);
			var thisWidth = thisImage.width();
			var pct = Math.round((xpos/thisWidth)*100)/100;
			var ipct = Math.abs(Math.round(((xpos-thisWidth)/thisWidth)*100)/100);
			thisImage.css({ 'opacity' : ipct });
		});
	});
});
</script>