Ext.js Focus Styling and Tabs

Ext.js Focus Styling and Tabs

<!DOCTYPE html>
<html>
   <head>
      <link href = "https://cdnjs.cloudflare.com/ajax/libs/extjs/6.0.0/classic/theme-crisp/resources/theme-crisp-all.css"
         rel = "stylesheet" />
      <script type = "text/javascript"
         src = "https://cdnjs.cloudflare.com/ajax/libs/extjs/6.0.0/ext-all.js"></script>

      <script type = "text/javascript">
         Ext.onReady(function(){
            Ext.create('Ext.Button', {
               renderTo: Ext.getElementById('button1'),
               text: 'Button1',

               listeners: {
                  click: function() {
                     Ext.MessageBox.alert('Alert box', 'Button 1 is clicked');
                  }
               }
            });
            Ext.create('Ext.Button', {
               renderTo: Ext.getElementById('button2'),
               text: 'Button2',

               listeners: {
                  click: function() {
                     Ext.MessageBox.alert('Alert box', 'Button 2 is clicked');
                  }
               }
            });
            Ext.create('Ext.Button', {
               renderTo: Ext.getElementById('button3'),
               text: 'Button3',

               listeners: {
                  click: function() {
                     Ext.MessageBox.alert('Alert box', 'Button 3 is clicked');
                  }
               }
            });
         });     
      </script>
   </head>

   <body> <p>Please click the button to see event listener:</p>
      <span id = "button3"/>
      <span id = "button2"/>
      <span id = "button1"/>
   </body>
</html>