YUI 3 error 'B.Lang is Undefined' yui-min.js line 7

Im just started to play around with and learn YUI3 however even my very early experiments are failing. Ive made a very simple first script however the page errors on load straight away in firebug with 'B.Lang is Undefined' yui-min.js line 7. Anyone got any ideas?

<html>
<head>
    <script src="http://yui.yahooapis.com/3.4.1/build/yui/yui-min.js"></script>
    <title>Untitled 2</title>
    <style>
        #container{
            width: 200px;
            height: 40px;
            padding: 5px;
            text-align: center;
            border: 1px solid #ccc;
            background-color: #ccc;   
        }
    </style>
    <script>

    YUI.use('node', function(Y){

        Y.one("#container").on('click', function(){
            alert("hello world"); 
        });
    })

    </script>
</head>

<body>

<div id="container">CLICK</div>

</body>
</html>

Solution

You need () after YUI:

YUI().use('node', function(Y){

    Y.one("#container").on('click', function(){
        alert("hello world"); 
    });
});

You'd put a config object in there later if you want control over various aspects, like setting event callbacks, eg:

YUI({
    combine: true,
    insertBefore: 'insertScriptsBefore',
    onProgress: function(o) {
        //
    },
    onFailure: function(o) {
        //
    },
    onTimeout: function(o) {
        //
    }
}).use('node', function(Y){

    Y.one("#container").on('click', function(){
        alert("hello world"); 
    });
});