window.addEventListener('load', function() { var status = document.getElementById("status"); function updateOnlineStatus(event) { var condition = navigator.onLine ? "online" : "offline"; status.className = condition; status.innerHTML = condition.toUpperCase(); log.insertAdjacentHTML("beforeend", "Event: " + event.type + "; Status: " + condition); } window.addEventListener('online', updateOnlineStatus); window.addEventListener('offline', updateOnlineStatus); });