javascript - get top offset of a div on window scroll -

i'm trying top offset of element using code it's not working it's getting same position every time 108 , not changing though margin-top 100px only

http://jsfiddle.net/np16jm3o/1/

$(function() {         $(window).scroll(function() {             var container= $("#container");             console.log(container.offset().top);         });     }); 

html code:

<div id="container" style="float: left; width: 100%; background: #ccc; height: 1200px; margin-top: 100px;"> 

the offset function returns position relative document, not offset of element itself, parent(s). when @ example in fiddle, can see body has margin of 8 px, resulting in 108px saw.

if want offset relative parent, substract offset of parent. use .scrolltop function height scrolled if want position relative page.