Get horizontal scroll event in js

You can handle horizontal scrolling by :

$("#someContainer").on("scroll", function (e) {
            horizontal = e.currentTarget.scrollLeft;
            vertical = e.currentTarget.scrollTop;
            });

In this case this bind all kind of scroll events on this element so you can also handle

Vertical by e.currentTarget.scrollTop

and

Horizontal by e.currentTarget.scrollLeft