jQuery: Mapping an array

The jQuery Code START
    
    <script type="text/javascript" src="./jquery-1.5.1.js"></script>
    <script src="http://code.jquery.com/jquery-latest.js"></script>
  
    <script type="text/javascript">
      $(document).ready(function(){
    
        var array = [1, 2, 3, 4, 5];
        $("#div1").text("Original: " + array.join(", "));

        array = jQuery.map(array, function (a) { 
            return a + a; 
        });

        $("#div2").text("Doubled: " + array.join(", "));

      });
    </script>
  </head>

  <body>
    <h1>jQuery: Mapping an array</h1>
    <div id="div1"></div>
    <div id="div2"></div>