Scrolling webpage

let scrollerID;
let paused = true;
let speed = 3; // 1 - Fast | 2 - Medium | 3 - Slow
let interval = speed * 5;

function startScroll(){
   
    let id = setInterval(function() {
        window.scrollBy(0, 2);
        if ((window.innerHeight + window.scrollY) >= document.body.offsetHeight) {
            // Reached end of page
         
            stopScroll();
        }
    }, interval);
 
    return id;
}

function stopScroll() {
  
    clearInterval(scrollerID);
   
}

function checkScroll(event) {
   // commenting out the below code as we need the scroll to work on every key press
    //if (event.which == 13 || event.keyCode == 13) {
          console.log(event.type);
          console.log(paused);
        if(paused == true) {
            scrollerID = startScroll();
            paused = false;
           console.log(scrollerID);
        }
        else {
            stopScroll();
           paused = true;
        }
   // }
}
document.body.addEventListener('keypress',checkScroll , true);
document.body.addEventListener('click',checkScroll , true);


window.onload = checkScroll;