https://www.gocar.ie/wp-content/themes/gocar/assets/js/is-gocar-for-me.js

1YUI().use('node', 'anim', 'transition', 'event', function (Y) {
2    var view = Y.one("body").get("viewportRegion").height;
3    
4    var m1l = Y.one('#m1-left').getY();
5    var m2l = Y.one('#m2-left').getY();
6    var m3l = Y.one('#m3-left').getY();
7    var m4l = Y.one('#m4-left').getY();
8    
9    var m1r = Y.one('#m1-right').getY();
10    var m2r = Y.one('#m2-right').getY();
11    var m3r = Y.one('#m3-right').getY();
12
13    function animate(newH){
14        var anim = new Y.Anim({
15            node: '#timeline',
16            to: {
17                height: newH
18            }
19        });
20        anim.run();
21    }
22
23    Y.one("#m1-left").addClass('fadeInLeft');
24    Y.one("#m1-right").addClass('fadeInRight');
25
26    Y.on('scroll', function(e){
27        var curScrollPos = Y.one('body').get('docScrollY');
28        var curHeight = view + curScrollPos;
29
30        if (curHeight > m2l) {
31            Y.one("#m2-left").addClass('fadeInLeft');
32            animate(421);
33        }
34
35        if (curHeight > m3l) {
36            animate(925);
37        }
38
39        if (curHeight > m4l) {
40            Y.one("#m4-left").addClass('fadeInLeft');
41            animate(1440);
42        }
43
44        if (curHeight > m2r) {
45         Y.one("#m2-right").addClass('fadeInRight');
46        }
47
48        if (curHeight > m3r) {
49         Y.one("#m3-right").addClass('fadeInRight');
50        }
51    });
52});