<?xml version="1.0" encoding="utf-8"?>
  <mx:VBox 
          xmlns:mx="http://www.adobe.com/2006/mxml" 
          xmlns:sides="view.sides.*">        
  
          <mx:Script>
                  <![CDATA[
                          import com.adobe.ac.mxeffects.Flip;
                          import com.adobe.ac.mxeffects.DistortionConstants;
                          
                          private function flipToRegistration() : void
                          {
                                  var e : Flip = new Flip( login );
                                  e.siblings = [ registration ];
                                  e.direction = DistortionConstants.RIGHT;
                                  e.duration = 2000;
                                  e.play();
                          }
                          
                          private function flipToLogin() : void
                          {
                                  var e : Flip = new Flip( registration );
                                  e.siblings = [ login ];
                                  e.direction = DistortionConstants.LEFT;                                        
                                  e.duration = 2000;
                                  e.play();
                          }
                  ]]>
          </mx:Script>
          
          <mx:ViewStack id="loginViewStack">
          
                  <sides:Login id="login" title="Login" change="flipToRegistration();"/>
                  <sides:Registration id="registration"  title="Registration" change="flipToLogin();"/>
          
          </mx:ViewStack>
          
  </mx:VBox>