set fileExists to "no"
tell application "Finder"
    if exists POSIX file "/tmp/oldvolume" then
        set fileExists to "yes"
    end if
end tell

tell application "iTunes"
    if fileExists = "yes" then
        set target to do shell script "cat /tmp/oldvolume"
        set target to target * 1
        repeat while sound volume < target
            set sound volume to (sound volume + 1)
        end repeat
        do shell script "rm /tmp/oldvolume"
    else
        do shell script "echo " & sound volume & " > /tmp/oldvolume"
        set target to (sound volume / 2)
        repeat while sound volume > target
            set sound volume to (sound volume - 1)
        end repeat
    end if
end tell