Flex: How can I pop up a component in the center of the user's viewable area?
<?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"
               width="3000" height="2000"
               creationComplete="creationCompleteHandler(event)">

  <fx:Script>
    <![CDATA[

      import mx.managers.PopUpManager;
      import spark.components.TitleWindow;

      public var myWindow:TitleWindow = new TitleWindow;

      protected function creationCompleteHandler(event:FlexEvent):void
      {
        myWindow.title = "My Title Window";
        PopUpManager.addPopUp(myWindow, DisplayObject(FlexGlobals.topLevelApplication), false);
        PopUpManager.centerPopUp(myWindow);
      }

    ]]>
  </fx:Script>

  <s:BorderContainer width="3000" height="2000" backgroundColor="0x000000" />
</s:Application>

+==========================+---------------------+
|      Viewable Area       |                     |
|                          |                     |
|     +-------------+      |                     |
|     |  I want the |      |                     |
|     |   popup to  |      |                     |
|     |   go here.  |      |                     |
|     +-------------+      |                     |
|                          |                     |
|                          |                     |
+==========================+                     |
|                                                |
|                Rest of Application             |
|                                                |
|                                                |
|                                                |
|                                                |
+------------------------------------------------+

+------------------------------------------------+
|                                                |
|                Rest of Application             |
|                                                |
|                                                |
|                +===========================+   |
|                |       Viewable Area       |   |
|                |                           |   |
|                |      +-------------+      |   |
|                |      |  I want the |      |   |
|                |      |   popup to  |      |   |
|                |      |   go here.  |      |   |
|                |      +-------------+      |   |
|                |                           |   |
|                |                           |   |
|                +===========================+   |
|                                                |
+------------------------------------------------+

dlg.x = (this.stage.stageWidth / 2) - (dlg.width / 2);
dlg.y = (this.stage.stageHeight / 2) - (dlg.height / 2);