（一）引用资源
应用extjs需要在页面中引入extjs的样式及extjs库文件，样式文件为resources/css/ext-all.css，extjs的js库文件主要包含两个，adapter/ext/ext-base.js及ext-all.js，其中ext-base.js表示框架基础库，ext-all.js是extjs的核心库。adapter表示适配器，也就是说可以有多种适配器，因此，可以把adapter/ext/ext-base.js换成adapter/jquery/ext-jquery-adapter.js，或adapter/prototype/ext-prototype-adapter.js等。
代码如下：
代码
<link rel="stylesheet" type="text/css" href="extjs/resources/css/ext-all.css" />
<script type="text/javascript" src="extjs/adapter/ext/ext-base.js"></script>
<script type="text/javascript" src="extjs/ext-all.js"></script>
<script type="text/javascript" src="extjs/adapter/ext/ext-base.js"></script>
<script type="text/javascript" src="extjs/ext-all.js"></script>
（二）第一个ExtJS程序-HelloWorld
代码
<html xmlns="http://www.w3.org/1999/xhtml " >
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>ExtJS</title>
<link rel="stylesheet" type="text/css" href="extjs/resources/css/ext-all.css" />
<script type="text/javascript" src="extjs/adapter/ext/ext-base.js"></script>
<script type="text/javascript" src="extjs/ext-all.js"></script>
<script>
Ext.onReady(function()
{
Ext.MessageBox.alert("hello","Hello,easyjf open source");
});
</script>
</head>
<body>
</body>
</html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>ExtJS</title>
<link rel="stylesheet" type="text/css" href="extjs/resources/css/ext-all.css" />
<script type="text/javascript" src="extjs/adapter/ext/ext-base.js"></script>
<script type="text/javascript" src="extjs/ext-all.js"></script>
<script>
Ext.onReady(function()
{
Ext.MessageBox.alert("hello","Hello,easyjf open source");
});
</script>
</head>
<body>
</body>
</html>
