How to add active class to slide in jCarouselLite?

Question

JavaScript

Good afternoon. The point is this. There is a slider that works with jCarouselLite. Scrolls one slide at a time. How, when switching, to determine the current slide and add the .active class to it? I know that the plugin has an afterEnd parameter in which you can write a function. But what to write in a function, there are not enough brains.

Note: must be done without changing the source code of the plugin itself.

<span class="prev"></span>
<div class="photoSlider">
  <ul class="imageList">
    <li class="imageItem"><img src="image.jpg"></li>
    <li class="imageItem"><img src="image.jpg"></li>
    <li class="imageItem"><img src="image.jpg"></li>
    <li class="imageItem"><img src="image.jpg"></li>
  </ul>
</div>
<span class="next"></span>

$('.photoSlider').jCarouselLite({
            btnNext: '.next',
            btnPrev: '.prev',
            circular: false,
            mouseWheel: true,
            visible: 1
});

Answer 1

You have some kind of galley slider. Since even the active class does not hang
https://www.google.ru/search?q=jCarouselLite&oq=jC...