JSFiddle - React, Tailwind, and code Playground

HTML

<html>
<head>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.6.1/jquery.js"></script>
<script>
  $(function() {
    window.onerror = function(e) { window.alert(e); };
    var i = 0;
    $('body').delegate('div', 'mouseleave', function() {
      $("#info").val(++i);
    });
  });
</script>
</head>
<body>
<input type="text" id="info">
<div style="overflow: scroll; height: 100px; width: 300px" id="x">
  <div id="y" style="background: #ffc; height: 100px; width: 300px"></div>
</div>
</body>
</html>