/* the document element root () */
const ROOT = document.documentElement;
function ScrollTo() {
}
function ShowElement() {
}
function HideElement() {
}
function DetectPageScroll() {
/* Maximum number of pixels that can be scrolled by the user */
let scrollTotal = ROOT.scrollHeight - ROOT.clientHeight;
if ((ROOT.scrollTop / scrollTotal ) > 0.80) {
//show button
} else {
//hide button
}
}
document.addEventListener("scroll", DetectPageScroll);