登陆前后的窗口

<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009" 
               xmlns:s="library://ns.adobe.com/flex/spark" 
               xmlns:mx="library://ns.adobe.com/flex/mx" 
               xmlns:views="views.*"    
               applicationComplete = "init()"
             >
    <s:layout>
        <s:VerticalLayout paddingTop="20" paddingLeft="20"/>
    </s:layout>
    <s:states>
        <s:State name="login" stateGroups="loggedOut"/>
        <s:State name="computers" stateGroups="loggedIn"/>
        <s:State name="info" stateGroups="loggedIn"/>
        <s:State name="tv" stateGroups="loggedIn"/>
    </s:states>
    <s:Panel includeIn="loggedOut" title.login="从这里登陆">
        <s:layout>
            <s:VerticalLayout/>
        </s:layout>
        <mx:Form>
            <mx:FormItem label="用户名" >
                <s:TextInput/>
            </mx:FormItem>
            <mx:FormItem label="密码">
                <s:TextInput/>
            </mx:FormItem>
        </mx:Form>
        <mx:ControlBar>
            <s:Button label="登陆" click="currentState='computers'"/>
        </mx:ControlBar>
    </s:Panel>
    <s:HGroup includeIn="loggedIn">
        <s:ButtonBar dataProvider ="{contentStack}"/>
        <s:Button label="退出" color="black" click="currentState='login'"/>
    </s:HGroup>
    <mx:ViewStack id="contentStack" includeIn="loggedIn">
       <mx:Canvas id="computers" backgroundColor="#ffffcc" label="电脑" width="100%" height="100%">
           <mx:Label text="电脑啊电脑啊"/>
       </mx:Canvas>
        <mx:Canvas id="infoform" backgroundColor="#ffccff" label="信息" width="100%" height="100%">
            <mx:Label text="信息啊信息啊"/>
        </mx:Canvas>
        <mx:Canvas id="tvview" backgroundColor="#ccffcc" label="电视" width="100%" height="100%">
            <mx:Label text="电视啊电视啊"/>
        </mx:Canvas>
    </mx:ViewStack>

</s:Application>