Get position on window scroll

position-on-scroll-snippet.js

/* This is a snippet found on stackoverflow: http://stackoverflow.com/questions/3714628/jquery-get-the-location-of-an-element-relative-to-window
*/

function log(txt) {
  $("#log").html("location : <b>" + txt + "</b> px")
}

$(function() {
  var eTop = $('#element').offset().top; //get the offset top of the element
  log(eTop - $(window).scrollTop()); //position of the ele w.r.t window

  $(window).scroll(function() { //when window is scrolled
    log(eTop - $(window).scrollTop());
  });
});