Simple UJS example

<html>
<head>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.0/jquery.min.js"
        type="text/javascript"></script>
<script type="text/javascript">

  $(function() {                         // in jQuery, $() appends an onLoad handler to document
    $('#myAlert').click(function () {    // adds an onClick handler to #myAlert
      alert(this.getAttribute('data-message')); return false;
      })
    // we could add other elements' event handlers here
  });
</script>

</head>
<body>
<p><a href="#" id="myAlert" data-message="Hello from UJS">Click Here</a></p>

</body>

</html>