Retrieve the position (X,Y) of an HTML element relative to the browser window

Question

I want to know how to get the X and Y position of HTML elements such as img and div in JavaScript relative to the browser window.

Answer 1

The libraries go to some lengths to get accurate offsets for an element.
here's a simple function that does the job in every circumstances that I've tried.

function getOffset( el ) {
    var _x = 0;
    var _y = 0;
    while( el && !isNaN( el.offsetLeft ) && !isNaN( el.offsetTop ) ) {
        _x += el.offsetLeft - el.scrollLeft;
        _y += el.offsetTop - el.scrollTop;
        el = el.offsetParent;
    }
    return { top: _y, left: _x };
}
var x = getOffset( document.getElementById('yourElId') ).left;