when i was trying to get return value from lua script (with which sql query was processed),

<action application="set" data="myvar=${expand(luarun GetDataFromDB.lua ${caller_id_number})}"/>

<action application="info" data="myvar=${myvar}"/>

GetDataFromDB.lua

--------------------------------------

callerid = argv[1]

-- DB sql query

...

varout = callerid..'abc'

return varout

the info shows "myvar=+OK.......", then i tried

<action application="set" data="myvar=${expand(lua GetDataFromDB.lua ${caller_id_number})}"/> -- using lua 

GetDataFromDB.lua instead of luarun GetDataFromDB.lua

the info shows an empty string, "myvar=".

how to get the return value from lua script?