How to add a JavaScript when the browser changes from working online to working offline

Try to disconnect from the internet to toggle between working online and offline.

index.html

Example: HTML

<!DOCTYPE html>
<html>
<body ononline="onFunction()" onoffline="offFunction()">

<p>Try to disconnect from the internet to toggle between working online and offline.</p>

<script>
function onFunction() {
  alert ("Your browser is working online.");
}

function offFunction() {
  alert ("Your browser is working offline.");
}
</script>

</body>
</html>

Output should be:

Type:	html
Category:	Web Tutorial
Sub Category:	HTML Window Event Attributes
Uploaded by:	Admin