Kirupa Pop-Up Window Tut From An External Swf Help!

I have been using the pop-up tut

http://www.kirupa.com/developer/mx/centered_popup.htm

However, the button i need it to work on is in an external swf do i have to change any of the script for it to still work? Perhaps add a _root but i was not sure where to put it.

Thanks for any help::slight_smile: