Small JS Coding sidekick needed

Im am not too much into js and need a small extension of a given js. My JS folds up a Laptop by getting seperate images on scroll. Just like here [login to view URL] The Job must be done today Script: const html = [login to view URL]; const canvas = [login to view URL]("macbook"); const context = [login to view URL]("2d"); const frameCount = 121; const currentFrame = index => ( `[login to view URL]${[login to view URL]().padStart(4, '0')}.jpg` ) const preloadImages = () => { for (let i = 1; i < frameCount; i++) { const img = new Image(); [login to view URL] = currentFrame(i); } }; const img = new Image() [login to view URL] = currentFrame(1); canvas.width=1096; canvas.height=728; img.onload=function(){ [login to view URL](img, 0, 0); } const updateImage = index => { [login to view URL] = currentFrame(index); [login to view URL](img, 0, 0); } [login to view URL]('scroll', () => { const scrollTop = [login to view URL]; const maxScrollTop = [login to view URL] - [login to view URL]; const scrollFraction = scrollTop / maxScrollTop; const frameIndex = [login to view URL]( frameCount - 1, [login to view URL](scrollFraction * frameCount) ); requestAnimationFrame(() => updateImage(frameIndex + 1)) }); preloadImages() HMTL <canvas id="macbook" /> The TASK: 1. If scrolled up image 90 is reached add class to body "reached-90" and add class to #macbook "reached-open90". Remove classes if scrolled down to a lower number image. 2. If scrolled up image 110 is reached add class to body "reached-110" and add class to #macbook "reached-open110". Remove classes if scrolled down to a lower number image. 3. If scrolled up image 121 is reached add class to body "reached-121" and add class to #macbook "reached-open121". Remove classes if scrolled down to a lower number image. I have jQuery on Page. Delivery: Send the altered script. I will build it into page. The Job might be interesting as I want to do more Apple like interactions and animations infuture on my page