let lazyimages = [].slice.call(document.querySelectorAll("img.lazy"));

if ("IntersectionObserver" in window) {
    let observer = new IntersectionObserver((entries, observer) => {
        entries.forEach(function(entry) {
            if (entry.isIntersecting) {
                let lazyimage = entry.target;
                lazyimage.src = lazyimage.dataset.src;
                lazyimage.srcset = lazyimage.dataset.srcset;
                lazyimage.classList.remove("lazy");
                observer.unobserve(lazyimage);
            }
        });
    });

    lazyimages.forEach((lazyimage) => {
        observer.observe(lazyimage);
    });
}