Property not being remembered in itunes script

I’m trying to bypass the annoying dialog box in iTunes when you want to delete something. However, the property is not being remembered, so even if you click “Don’t Prompt Again” it prompts you again. Anyone know why?

property confirm : true

tell application "iTunes"
	set sel to selection
	if confirm is true then set toContinue to button returned of (display dialog "	WARNING:" & return & "This script will delete the selected file immediately, sending it to the trash. Since the point is to get rid of the dialog box, this will not appear again if you choose \"Don't Prompt Again\". You have been warned." buttons {"Cancel", "Don't Prompt Again", "Prompt Again"} with icon caution cancel button 1)
	if toContinue is "Don't Prompt Again" then set confirm to false
	repeat with toDelete in sel
		set deleteFile to location of toDelete
		tell application "Finder" to move deleteFile to trash
		delete toDelete
	end repeat
end tell


the most reliable way to get data persistence of properties is to save the script as application