The Publish Preview command exports the file and opens the preview in the default browser. If you preview a QuickTime video, Publish Preview starts the QuickTime video Player. If you preview a projector, Flash starts the projector.
Select File > Publish Preview, and
select the file format to preview.
Using the current Publish Settings values, Flash creates a file of the specified type in the same location as the FLA file. This file remains in this location until you overwrite or delete it.