Flex :: Air - Get The Parent Of A Custom Grid Column Filter Editor And Open A Popup Window?

I am trying to figure out how to open a pop up window in my Air application, in a secondary Window, instead of the main application window.I am using the ReusableFX components, which include a custom DataGrid with filtering and other capabilities. The filtering feature displays a pop up window via PopUpManager when you click on the top of a column in the grid.

PopUpManager.addPopUp(this, FlexGlobals.topLevelApplication as DisplayObject);

The problem is that the pop up window opens in the main application - I am assuming because of the 'topLevelApplication' reference.So, I need a way to open this window in the current Air "s:Window". I am assuming I need a way to walk up : this.parent.parent or this.owner.owner - though I have tried that and it did not seem to work (it said null reference).OR, is there a way to get the current top most window / component (NOT the main application / window)?

Update:I decided to create a new project for the component, and add in the Air libraries. Now I am able to access the "NativeApplication.nativeApplication.activeWindow" call. That gives me the correct Air window. However, it does not seem to be working:

PopUpManager.addPopUp(this, NativeApplication.nativeApplication.activeWindow as DisplayObject);

My popup does not appear. I am assuming because "activeWindow" is not actually a DisplayObject?(so how do I get the DisplayObject if that's the case?)