Is this an elegant way to make elements fade in wh

Question

My task was to make fade in for elements while scrolling, like this - http://layot.prestatrend.com/ I have made it with the help of such jQuery code I've gathered from two sources:

<script type="text/javascript">
 $(document).ready( function() {

 tiles = $('.ajax_block_product').fadeTo(0,0);

 $(window).scroll(function(d,h) {
    tiles.each(function(i) {
        a = $(this).offset().top + $(this).height();
        b = $(window).scrollTop() + $(window).height();
        if (a < b) $(this).fadeTo(500,1);
    });
 });

 function inWindow(s){
  var scrollTop = $(window).scrollTop();
  var windowHeight = $(window).height();
  var currentEls = $(s);
  var result = [];
  currentEls.each(function(){
    var el = $(this);
    var offset = el.offset();
    if(scrollTop <= offset.top && (el.height() + offset.top) < (scrollTop +    windowHeight))
      result.push(this);
  });
  return $(result);
}

inWindow('.ajax_block_product').fadeTo(0,1);

});
</script>

Is this an elegant solution or is there a way to make the code shorter and more elegant?