JSFiddle - React, Tailwind, and code Playground

by softvar

JavaScript

var showMsgTimer;

window.onbeforeunload = function(evt) {
    var message = 'Please Stay on this page and we will show you a secret text.';
    showMsgTimer = window.setTimeout(showMessage, 100);

    evt = evt || window.evt;
    evt.returnValue = message;

    return message;
}

window.onunload = function () {
    clearTimeout(showMsgTimer);
}

function showMessage() {
    alert("You've been trolled!");
}