the switch went unnoticed by audiences for years until freeze-frame analysis clearly revealed that it was Vera Miles and not Janet Leigh in the shower during the trailer. In the United States there are dozens of companies, many of which are in Los Angeles and New York City, that specialize in the creation of film trailers. The trailer may be created at agencies (such as The Cimarron Group, MOJO, The Ant Farm, Ben Cain, Aspect Ratio, Flyer Entertainment, Trailer Park, Buddha Jones) while the film itself is being cut together at the studio. Since the edited film does not exist at this point, the trailer editors work from rushes or dailies. Thus, the trailer may contain footage that is not in the final movie, or the trailer editor and the film editor may use different takes of a particular shot. Another common technique is including music on the trailer which does not appear on the movie's soundtrack. This is nearly always a requirement, as trailers and teasers are created long before the composer has even been hired for the film score—sometimes as much as a year ahead of the movie's release date—while composers are usually the last creative people to work on the film. Some trailers that incorporate material not in the film are particularly coveted by collectors, especially trailers for classic films. For example, in a trailer for Casablanca the character Rick Blaine says, "OK, you asked for it!" before shooting Major Strasser; this line of dialogue is not spoken in the final film. Accusations of misdirection Over the years, there have been many instances where trailers have been purported to give misleading representations of their films. They may give the impression that a celebrity who only has a minor part in the film is one of the main cast members, or advertising a film as being more action-packed than it is. These tricks are usually done to draw in a larger audience. Sometimes the trailers include footage not from the film itself. This could be an artistic choice, or because the trailer was put together before the film's final cut, but at other times it is to give the audience a different impression of the movie. Then trailers could be misleading in a 'for the audience's own good' kind of way, in that a general audience would not usually see such a film due to preconceptions, and by