ASK YOUR QUESTION

show alert box before leaving webpage

{ // deep_execution_view
const authorName = "Ankit Agrawal";
//
const publishDate = "June 18, 2015";

you can do this easily by using java script function 

<script>
$(window).bind(&#039;beforeunload&#039;, function(e){
     return &#039;You are leaving this now&#039;;
});
</script>
}