index.html

 <!DOCTYPE HTML>
<head>
    <title>Ext JS 4.X Demo App</title>

    <link rel="stylesheet" type="text/css" href="ext/resources/css/ext-all.css">
    <link rel="stylesheet" type="text/css" href="css/app.css">

    <script type="text/javascript" src="ext/ext-all-debug.js"></script>
    <!--<script type="text/javascript" src="ext/ext-all-dev.js"></script>-->
    <script type="text/javascript" src="common.js"></script>
    <script type="text/javascript" src="app.js"></script>
</head>
 <html>
</html>