QuickTime 4 Reference

The quit command

The quit command closes all open files and quits QuickTime Player. The quit command has an optional parameter saving that specifies whether and how changes should be saved prior to quitting.

quit: Quit an application program

quit

[saving yes/no/ask] -- specifies whether changes
should be saved before quitting

For example:

tell application "QuickTime Player"

quit

end tell