так?
<!DOCTYPE html>
<html>
<head>
</head>
<body>
<script type="text/javascript" src="js/ext-4.2.1.883/ext-all.js"></script>
<link rel="stylesheet" type="text/css" href="ext-4.2.1.883/resources/css/ext-all.css">
<script type="text/javascript">
var openTab;
Ext.onReady(function() {
openTab = function (number)
{
tabs.setActiveTab(number);
}
var tabs = Ext.widget('tabpanel',
{
renderTo: Ext.getBody(),
resizeTabs: true,
enableTabScroll: true,
width: 300,
height: 250,
items: [
{
title: 'Tab 1',
iconCls: 'tabs',
html: '<a href="#" onclick="openTab(1);">открыть вторую вкладку, епта!!</a><br/><br/>'
},
{
title: 'Tab 2',
iconCls: 'tabs',
html: 'Tab Body2222<br/><br/>'
},
{
title: 'Tab 3',
iconCls: 'tabs',
html: 'Tab Body3333<br/><br/>'
}]
});
});
</script>
</body>
</html>