if (Math.abs(container.scrollTop() - container.data('lazyload:lastCheckedScrollTop')) > settings.scrollThreshold) {
container.data('lazyload:lastCheckedScrollTop', container.scrollTop());
if (Math.abs(container.scrollTop() - container.data('lazyload:lastCheckedScrollTop')) > settings.scrollThreshold) {
container.data('lazyload:lastCheckedScrollTop', container.scrollTop());