Ext 4.2 - Very Simple (Stupid) Gmap - Marker and InfoWindow

HTML

<script src="http://docs.sencha.com/extjs/4.2.0/extjs-build/examples/ux/GMapPanel.js"></script>
<script src="https://maps.googleapis.com/maps/api/js?key=AIzaSyAZx1jmE9yB533ED9suD13buyd0pEfmTzI&amp;sensor=false&amp;dummy=.js"></script>
<script src="http://www.msg360.co.uk/emails/sample/Scripts/infobubble-compiled.js"></script>
<link rel="stylesheet" href="http://cdn.sencha.com/ext/gpl/4.2.0/resources/css/ext-all.css">

CSS

.x-border-box .reset-box-sizing * {
    box-sizing: content-box;
}

JavaScript

Ext.onReady(function() {
    
    var w = Ext.create('Ext.window.Window', {
        title: 'Gmap',
        height: 400,
        width: 600,
        layout: 'border',
        items: [
            {
                title: 'Message List',
                region: 'south',            
                height: 50,
                
                split: true,
                collapsible: true,
                margins: '0 5 5 5',
                collapsed: true
            },{
                region: 'west',
                title: 'Tree',
                collapsible: true,
                width: 100,
                items: [
                {
                  xtype: 'button',
                  text: 'add',
                  handler: addInfoWindow // reference to event handler function 
                }]
            },{
                xtype: 'gmappanel',
                region: 'center',
                cls: 'reset-box-sizing',
                center: new google.maps.LatLng(53.5267, -1.13330),
                mapOptions: {
                    zoom: 16,
                    mapTypeId: google.maps.MapTypeId.ROADMAP                    
                }
            }            
        ]
    });
    
    /**
     * Just example, do not write code like this!
     * GMApPanel source code 
     * http://docs.sencha.com/extjs/4.2.0/extjs-build/examples/ux/GMapPanel.js
     */
        
    
    // get the map reference
    var map = w.down('gmappanel');   
    function openInfoWindow(content, marker) {
      // create a info window
      var infowindow = new google.maps.InfoWindow({ 
          content: content,
          size: new google.maps.Size(50,50)
      });               
      
        infoBubble = new InfoBubble({
                content: '<div class="example">Some label</div>',
                //position: new google.maps.LatLng(53.5267, newlong),
                shadowStyle: 1,
                padding: 10,
                borderRadius: 5,
                minWidth:...