-- gets the screensaver preferences file
set screensaver to "~/Library/Preferences/ByHost/" & (do shell script "cd ~/Library/Preferences/ByHost;ls | grep 'com\\.apple\\.screensaver\\..\\{12\\}\\.plist' | sed 's/\\.plist//'")

-- saves the values that will be modified
set lastPictureDirectoryChosen to (do shell script "defaults read " & screensaver & " lastPictureDirectoryChosen")

set modulePath to (do shell script "defaults read " & screensaver & " modulePath")

-- writes the new values
do shell script "defaults write " & screensaver & " lastPictureDirectoryChosen /Users/paul/Pictures/Airplanes"

do shell script "defaults write " & screensaver & " modulePath \"/System/Library/Frameworks/ScreenSaver.framework/Resources/Pictures Folder.saver\""

-- runs the screensaver background
-- from bgscreensaver application
set isrunning to do shell script "ps -ax | grep ScreenSaver.framework | grep -v grep | awk '{print $1}'"

if isrunning is "" then
	do shell script "/System/Library/Frameworks/ScreenSaver.framework/Resources/ScreenSaverEngine.app/Contents/MacOS/ScreenSaverEngine -background > /dev/null 2>&1 &"
else
	do shell script "kill -9 " & isrunning & " > /dev/null 2>&1"
end if

-- restores the old values for the actual screensaver
do shell script "sleep 2; defaults write " & screensaver & " lastPictureDirectoryChosen " & "\"" & lastPictureDirectoryChosen & "\""

do shell script "defaults write " & screensaver & " modulePath " & "\"" & modulePath & "\""