Vigilar estado de checkbox

<!DOCTYPE html>
<html>

<head>
  <script data-require="jquery@2.2.4" data-semver="2.2.4" src="https://ajax.googleapis.com/ajax/libs/jquery/2.2.4/jquery.min.js"></script>
  <link rel="stylesheet" href="style.css" />
  <script src="script.js"></script>
</head>

<body>
  <h1>Vigilar estado de checkbox</h1>
  <input type="checkbox" id="mi_caja" />
</body>

</html>

$(function() {
  $("#mi_caja").change(function(){
  alert("Cambio");
});
});

/* Styles go here */