enwin

// sticky element
var stickyHeader = document.querySelector( '.intro-banner' );

function handleFocus( e ){
  // don't try to change the scroll if the focused element is in the sticky element
  if( stickyHeader.contains( e.target )){
    return;
  }

  // quick & dirty client height on each focus

adactio

<?php

# Licensed under a CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
# http://creativecommons.org/publicdomain/zero/1.0/

if (!isset($_POST['source']) || !isset($_POST['target'])) {
  header($_SERVER['SERVER_PROTOCOL'] . ' 400 Bad Request');
  exit;
}