https://baljet.com/js/easySlider1.5.js

1(function($) {
2    easySlider = function(options){
3        var defaults = {
4            speed: 			500,
5            pause:			10000,
6            continuous:		true
7        };
8
9        var options = $.extend(defaults, options);        
10        var s;
11        var w ;       
12        var ts;
13        var t = 0;
14        
15        $(".arrow-right").click(function(){            
16            animateClick("next");
17            return false;
18        });
19        $(".arrow-left").click(function(){
20            animateClick("prev");
21            return false;
22        });
23
24        function animateClick(dir){
25             var src= $('.project .main-image-holder, .project-item.active .image-holder');
26            s = $("li", src).length;
27            ts = s-1;
28            w = $("li", src).width();
29            
30            src.find('li').removeClass('active');
31
32            var ot = t;
33            switch(dir){
34                case "next":
35                    t = (ot>=ts) ? (options.continuous ? 0 : ts) : t+1;
36                    break;
37                case "prev":
38                    t = (t<=0) ? (options.continuous ? ts : 0) : t-1;
39                    break;
40                default:
41                    break;
42            };
43            src.find('li').eq(t).addClass('active');
44            var diff = Math.abs(ot-t);
45            var speed = diff*options.speed;
46            if(!options.vertical) {
47                p = (t*w*-1);
48                src.find("ul").animate(
49                {
50                    marginLeft: p
51                },
52                speed
53                );
54            }
55            
56        };      
57    };
58})(jQuery);