FLV and Transparency

Hey guys… Well, I have a video, and I can take out the bg, but here is the part I’m not sure about. If I remove the background from a flv(flash video) file, when I import it into flash… will there be a white background? or will it be transparent? You know what I mean? Since the video will be a rectangle… will there be white around the edges of the person or not? Thnx guys.