https://www.autotesto.pl/blog/wp-content/themes/autotestoNew/js/fly.banner.js?ver=6.7.2

1(function($)
2{
3    $(function()
4    {
5        var $window = $(window),
6            $banner = $('.fly-banner'),
7            $footer = $($banner.data('fly-rel')),
8            top = $banner.data('fly-top'),
9            bS = 0,
10            eS = 0
11        ;
12
13        setTimeout(function()
14        {
15            bS = $banner.position()['top'];
16            eS = $footer.position()['top']
17                - $banner.height()
18                - top
19                - 50
20            ;
21
22        }, 1000);
23
24        function fly()
25        {
26            var isPinned = $banner.is('.fly-banner-pinned'),
27                scroll = $window.scrollTop()
28            ;
29
30            function pin()
31            {
32                if(isPinned)
33                {
34                    return;
35                }
36
37                $banner
38                    .addClass('fly-banner-pinned')
39                    .css({
40                        'top': top
41                    })
42                ;
43            }
44
45            function unpin()
46            {
47                if(!isPinned)
48                {
49                    return;
50                }
51
52                $banner
53                    .removeClass('fly-banner-pinned')
54                    .css({
55                        'top': 'auto'
56                    })
57                ;
58            }
59
60            (function()
61            {
62                if( bS < scroll &&
63                    eS > scroll
64                )
65                {
66                    pin();
67
68                    return;
69                }
70
71                unpin();
72
73            })();
74
75            setTimeout(fly, 100);
76        }
77
78        fly();
79    });
80})(jQuery);