QuickTime movies consist of two parts, the movie file (analogous to the film) and the QuickTime extension (analogous to the projector). An application having QuickTime capability does not actually store the code for the film, what is stored is a pointer to the movie file. When QuickTime detects that a movie file is changed or not in the location specified by the pointer, it goes through an automatic search procedure to attempt to locate the movie file. After a few seconds it will display a message indicating that it is searching (along with a stop button). If it can't find the file, it will display the standard file dialog and ask the user to find it. This search is performed by QuickTime and the alias manager, and is not under the direct control of the application using the movie.