Answers for "js element offset top"

js get element window offset top

var element = document.getElementById('myElement');
var topPos = element.getBoundingClientRect().top + window.scrollY;
var leftPos = element.getBoundingClientRect().left + window.scrollX;

offset in js

var d = document.getElementById("div1");
var topPos = d.offsetTop;
 
if (topPos > 10) {
  // object is offset more
  // than 10 pixels from its parent
}