How do you tell how effective your preload script is? Flash includes a utility called the Bandwidth Profiler for just such a purpose. The Bandwidth Profiler allows you to set the bandwidth most applicable . Moreover, both the streaming and the movement of the playhead can be viewed together so that you can quickly gauge whether an adjustment is necessary. The Bandwidth Profiler also gives you a great deal of detailed information about your movie: its file size , duration, and even the preload timea very important factor.