Returns the relative position of an element in the page

getElementPosition.js

// http://stackoverflow.com/questions/288699/get-the-position-of-a-div-span-tag

function getPos(el) {
  // yay readability
  for (var lx=0, ly=0;
       el != null;
       lx += el.offsetLeft, ly += el.offsetTop, el = el.offsetParent);
  return {x: lx,y: ly};
}