System event key codes not working on thunderbolt display

System event key codes not working on thunderbolt display

my applescript works when i am just using my MBPretina however if i have
my thunderbolt display turned in the script does not work
Here is the script which works perfectly on just the laptop
######## turn screen bright
repeat 25 times
tell application "System Events"
key code 113
end tell
end repeat
Terminal will display this if i am running on the thunderbolt
^[[28~^[[28~^{{... etc
does any one know the key code system events for thunderbolt or where i
may find them?
Thanks in advance