Lua Problem with advance

[Gothric]

I am writting script on advance and i have one question

i have a board with skills and if skill x == xxx then do something

but there is error in console if new skill is different than this one in table

i tried

skills - name of my board
if skills[skill] == nil then
return true
end

but it doesnt work

rep+

 

[Summ]

post the script.