[flexcoders] Applying a dissolve effect to a TitleWindow

[oneworld95]

Hi. I've got a TitleWindow that needs to dissolve in when the user
clicks the Button that creates it. The TitleWindow is in the Help.mxml
file and looks like this,

<?xml version="1.0" encoding="utf-8"?>
<mx:TitleWindow xmlns:mx="http://www.adobe.com/2006/mxml"; 
        layout="vertical" width="400" height="300" showCloseButton="true"
        close="titleWindow_Close(event);"
creationComplete="handleCreationComplete()">

        <mx:Script>
        <![CDATA[
            import mx.managers.PopUpManager;

            private function handleCreationComplete():void {
                // Center the TitleWindow container 
                // over the control that created it.
                PopUpManager.centerPopUp(this);
            }
            
            private function titleWindow_Close(event:Event):void {
                PopUpManager.removePopUp(this);
            }
        ]]>
    </mx:Script>
        <mx:HBox showEffect="{dissolveIn}" hideEffect="{dissolveOut}"> 
         
        <mx:Button 
            label="Cancel"
            click="titleWindow_Close(event);"/> 
    </mx:HBox> 
        <mx:Dissolve id="dissolveOut" duration="5000" alphaFrom="1.0"
alphaTo="0.0"/>
    <mx:Dissolve id="dissolveIn" duration="5000" alphaFrom="0.0"
alphaTo="1.0"/>

</mx:TitleWindow>

On the main Flex app, it calls the Help.mxml window like this,

            private function showLogin():void {
                // Create a non-modal TitleWindow container.
                var helpWindow:TitleWindow = 
TitleWindow(PopUpManager.createPopUp(this, Help, true));
            }

How do I apply an effect to this TitleWindow for when it's showing and
hiding? Thanks.

-Alex