Active menu Changer on Sticky Bar

I have designed a Parallax Page with Sticky Menu bar. I need to change the active menu on scrolling. I have made it to change the active class on Click event. But I need it to do for the scroll event.

Here is my HTML Code

<div class="main-menu">

    <ul>             
        <li><a class="active" href="#" data-delay="2000" data-appear="false" data-scrollto="#intro-slideshow">Home</a></li>
        <li><a href="#" data-delay="2000" data-appear="false" data-scrollto="#overview">Features</a></li>
        <li><a href="#" data-delay="2000" data-appear="false" data-scrollto="#categories">Categories</a></li>
        <li><a href="#" data-delay="2000" data-appear="false" data-scrollto="#contact">Contact Us</a></li>
    </ul>

</div>

Here is my JQuery Code for Onclick Active Menu Changer

$('*[data-scrollto]').click(function(){

        $( "a" ).removeClass( "active" );
        $(this).addClass("active");

        var dest = $(this).data('scrollto');                
        var pixels = $(dest).offset().top - 70;         
        var ms = Math.round(1000 + pixels/5);

        $('html, body').animate({               
            scrollTop: pixels
        }, ms, 'easeOutQuint');

    }); 

How do I change the active class on Scroll Event with the Data-Scrollto attribute ?

via Chebli Mohamed