How can I nicely animate between viewstacks

I have a little Adobe Air app and I want to have several 'views' within it. I can achieve these views using a ViewStack but am having difficulty finding a nice way to animate between them.

This is what I have tried and although it works, one view disappears before sliding into view when what I want is more like the DestroyTwitter app where the view and all controls slide out of view nicely:

<?xml version="1.0" encoding="utf-8"?>
<mx:WindowedApplication xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute" width="400" height="700" top="100" left="100" creationComplete="onComplete()">
    <mx:Script>
    <![CDATA[
        import mx.core.Application;
        private function onComplete():void
        {
            stack.selectedChild = stack1;
        }

        private function switchTab():void
        {
            if( stack.selectedChild == stack1 )
            {
                stack.selectedChild = stack2;
            }
            else
            {
                stack.selectedChild = stack1;
            }
        }
    ]]>
    </mx:Script>

    <mx:Move id="slideLeft" xFrom="{Application.application.width}" xTo="0" yTo="0" duration="500" />
    <mx:Move id="slideRight" xFrom="0" xTo="{Application.application.width}" duration="500" />

    <mx:ViewStack id="stack" width="200%" height="100%">
        <mx:VBox id="stack1" width="100%" height="100%" backgroundColor="white" hideEffect="{slideRight}" >
            <mx:Label text="Stack 1" />
            <mx:Button label="Switch" click="switchTab()" />
        </mx:VBox>

        <mx:VBox id="stack2" width="100%" height="100%" backgroundColor="#cdcdcd" hideEffect="{slideLeft}" >
            <mx:Label text="Stack 2" />
            <mx:Button label="Switch" click="switchTab()" />
        </mx:VBox>

    </mx:ViewStack>
</mx:WindowedApplication>

Has anyone got any nicer ideas to try, be grateful for any response?

Here is exactly what i wanted to achieve:

<?xml version="1.0" encoding="utf-8"?>
<mx:WindowedApplication xmlns:mx="http://www.adobe.com/2006/mxml" 
    layout="absolute" width="400" height="700" top="100" left="100" 
    horizontalScrollPolicy="off" verticalScrollPolicy="off"
    >

    <mx:Script>
        <![CDATA[
            import mx.core.Application;
        ]]>
    </mx:Script>


    <mx:states>
    <mx:State name="One">
            <mx:SetProperty target="{stack1}" name="x" value="0"/>
            <mx:SetProperty target="{stack1}" name="y" value="50"/>
            <mx:SetProperty target="{stack1}" name="width" value="{Application.application.width}"/>

            <mx:SetProperty target="{stack2}" name="x" value="{Application.application.width}"/>
            <mx:SetProperty target="{stack2}" name="y" value="50"/>
            <mx:SetProperty target="{stack2}" name="width" value="{Application.application.width}"/>
    </mx:State>

    <mx:State name="Two">
            <mx:SetProperty target="{stack1}" name="x" value="-{Application.application.width}"/>
            <mx:SetProperty target="{stack1}" name="y" value="50"/>
            <mx:SetProperty target="{stack1}" name="width" value="{Application.application.width}"/>

            <mx:SetProperty target="{stack2}" name="x" value="0"/>
            <mx:SetProperty target="{stack2}" name="y" value="50"/>
            <mx:SetProperty target="{stack2}" name="width" value="{Application.application.width}"/>
    </mx:State>
    </mx:states>


    <!-- Define Transition array with one Transition object.-->
    <mx:transitions>
        <!-- A transition for changing from any state to any state. -->
        <mx:Transition id="myTransition" fromState="*" toState="*">
            <mx:Parallel id="t1" targets="{[stack1,stack2]}">
                <mx:Move    duration="400"/>
            </mx:Parallel>
        </mx:Transition>
    </mx:transitions>

    <mx:HBox>
        <mx:Button label="Switch To Two" click="currentState='Two'" />
        <mx:Button label="Switch To One" click="currentState='One'" />
    </mx:HBox>

    <mx:Canvas id="stack1" x="0" y="50" width="100%" height="100%" borderThickness="1" borderStyle="solid">
        <mx:VBox width="100%" height="100%" backgroundColor="white">
            <mx:Label text="Stack 1" />
            <mx:Box backgroundColor="red" width="20" height="20" />
        </mx:VBox>
    </mx:Canvas>

    <mx:Canvas id="stack2" x="{Application.application.width}" y="50" width="100%" height="100%" borderThickness="1" borderStyle="solid">
        <mx:VBox width="100%" height="100%" backgroundColor="#cdcdcd">
            <mx:Label text="Stack 2" />
            <mx:Box backgroundColor="green" width="20" height="20" />
        </mx:VBox>
    </mx:Canvas>

</mx:WindowedApplication>