Dynamically importing gif's or pngs

Would anyone know if it would be possible to import gifs dynamically into flash at runtime? http://www.kirupa.com/developer/mx2004/xml_flash_photogallery.htm
I used this tutorial to make a photo gallery with an external xml file. I know IE doesnt like png’s but flash wont even import gifs only jpgs. This sux for me as i need a transparent background… someone helpppppppppppppppppppppppp