how do i import photo booth to imovie

Just downloaded the latest OS Maverick and the new imovie. Now we cannot figure out how to import Photo Booth movies to iMovie. It used to be so easy! What am I missing? Looks like they just want you to use the Built-In iSight. Any tips? We even tried exporting the PhotoBooth file, but it iMovie only recognizes it as a "document" and won't make eligible to download. Thanks for any help!