[jquery] jQuery: Scroll down page a set increment (in pixels) on click?

Just check this:

$(document).ready(function() {
    $(".scroll").click(function(event){
        $('html, body').animate({scrollTop: '+=150px'}, 800);
    });
});

It will make scroller scroll from current position when your element is clicked

And 150px is used to scroll for 150px downwards