Automating backup of Flash drives

(*
Original author:
Constantinos C. Neophytou
http://www.cneophytou.com/2007/03/06/automating-backup-of-flash-drives/

Amended original script to work with OSX Mavericks - skororu.deviantart.com
*)

property backup_script : "rsync.app"
property dialog_timeout : 30

on adding folder items to this_folder after receiving added_items
    try
        tell application "Finder"
            try
                repeat with i from 1 to number of items in added_items

                    set this_item to the item i of added_items

                    if (kind of this_item is "Volume") then
                        tell application "System Events" to set thefullpath to (POSIX path of this_item) & "/" & backup_script

                        if exists thefullpath as POSIX file then
                            set backupFile to POSIX file thefullpath as alias
                            open backupFile
                        end if
                    end if

                end repeat
            end try
        end tell
    end try
end adding folder items to