Watching Tutorial - BasicViewApp - View Transitions

Source Code:
BasicViewAppUserListView.mxml

<?xml version="1.0" encoding="utf-8"?>
<s:View xmlns:fx="http://ns.adobe.com/mxml/2009"
  xmlns:s="library://ns.adobe.com/flex/spark" title="Cool People"
  creationComplete="view1_creationCompleteHandler(event)">
 <fx:Declarations>
  <!-- Place non-visual elements (e.g., services, value objects) here -->
  <s:FlipViewTransition id="flipLeft" duration="300" direction="left" />
  <s:FlipViewTransition id="flipRight" duration="300" direction="right" />
 </fx:Declarations>
 
 <s:layout>
  <s:VerticalLayout paddingTop="10" />
 </s:layout>
 
 <fx:Script>
  <![CDATA[
   import mx.events.FlexEvent;
   
   import spark.events.IndexChangeEvent;
   
   protected function userList_changeHandler(event:IndexChangeEvent):void
   {
    // TODO Auto-generated method stub
    navigator.pushView(views.UserProfile, userList.selectedItem);
   }
   
   protected function view1_creationCompleteHandler(event:FlexEvent):void
   {
    // TODO Auto-generated method stub
    navigator.defaultPopTransition = flipRight;
    navigator.defaultPushTransition = flipLeft;
   }
   
  ]]>
 </fx:Script>