property plOld : "@@old@@"


global iTunesRunning, iTunesRunning, existsCurrent, ok_to_Idle

on run
	set ok_to_Idle to false
	set iTunesRunning to false
	set e to my running_apps()
	if e contains "iTunes" then
		set iTunesRunning to true
		tell me to purge_old()
	end if
end run


on purge_old()
	try
		tell application "System Events"
			set iTunesRunning to (exists process "iTunes")
		end tell
		
		if iTunesRunning then
			tell application "iTunes"
				repeat with everyTrack in every track of playlist plOld
					if everyTrack's rating < 20 then
						set everyTrack's rating to 0
					else
						set old to everyTrack's rating
						set everyTrack's rating to old - 20
					end if
				end repeat
			end tell
		end if
	end try
end purge_old

on running_apps()
	tell application "System Events"
		return (get name of every process)
	end tell
end running_apps