Help with folder action

hi,
i made these script so when i download a mp3 or aac file to my downloads folder it adds them to the itunes library
but i was wondering how i can make it play the song i just added if itunes is not playing any music…

also, i would like some help on understanding the Script Editor dictionary, for example how do i call stuff(properties or elements) of the class playlist in itunes ??

UPDATE!!: i was able to code it, see below…

HELP!! itunes opens when i enable this folder action, is there anyway to make it so that it runs it only when itunes is needed???

on adding folder items to this_folder after receiving added_items
	set added to 0
	tell application "Finder"
		repeat with aFile in added_items
			if the name of aFile ends with {".mp3"} ¬
				or the name of aFile ends with {".aac"} then
				tell application "Finder"
					try
						tell application "iTunes"
							if player state is stopped or player state is paused then
								set addedTrack to add aFile
								play addedTrack
							else
								add aFile
							end if
						end tell
					on error err
						display dialog err
					end try
				end tell
				set added to 1
			end if
		end repeat
		if added is 1 then
			display dialog ¬
				"Music files have been added to the iTunes Library."
			move aFile to trash
		end if
	end tell
end adding folder items to