I am getting an error in a lua script which I don’t understand. Why is it returning nil in the script yet something in the cli?

lua snippet:

user_data = session:getVariable('user_data 1000@192.168.10.29 var callgroup');

freeswitch.console_log("INFO", " UserData group " .. user_data .. "\n")

log:

2009-07-16 14:30:49.237343 [ERR] mod_lua.cpp:182 /usr/local/freeswitch/scripts/helloworld.lua:14: attempt to concatenate global 'user_data' (a nil value)

stack traceback:

        /usr/local/freeswitch/scripts/helloworld.lua:14: in main chunk

cli:

freeswitch@internal> user_data 1000@192.168.10.29 var callgroup

techsupport

Thanks, Lars