Add panel to window as items
<html> <head> <title>Hello World Window</title> <link rel="stylesheet" type="text/css" href="ext-3.0.0/resources/css/ext-all.css" /> <script type="text/javascript" src="ext-3.0.0/adapter/ext/ext-base.js"></script> <script type="text/javascript" src="ext-3.0.0/ext-all.js"></script> </head> <body> <script type="text/javascript"> Ext.onReady(function() { var panel1 = { html : 'I am Panel1', id : 'panel1', frame : true, height : 100 } var panel2 = { html : 'line 1<br/>line 2<hr>', id : 'panel2', frame : true } var myWin = new Ext.Window({ id : 'myWin', height : 250, width : 400, items : [ panel1, panel2 ] }); myWin.show(); }); </script> <div id='div1'>asdf</div> </body> </html>