Problem with custom function

[Maud Pie]

I have some problem with my custom function
Here function code:
Azarath_Acces_Groups = {}

function AzarathCreateAccesGroup(name,usergroup,blackorwhite,commandlist)
if name == "" then return false end
if not blackorwhite == "white" or not blackorwhite == "black" then return false end
if #commandlist < 1 then return false end
local tab = {}
tab.name = name
tab.usergroup = usergroup
tab.blackorwhite = blackorwhite
tab.commandlist = commandlist
local groupexist = false
for k,v in pairs(Azarath_Acces_Groups) do
if Azarath_Acces_Groups[k].name == name then
groupexist = true
end
end
if not groupexist then
table.insert(Azarath_Acces_Groups,tab)
end

end
I wan't to check if group exist don't add to table
Code I ran:
AzarathCreateAccesGroup(
"superadmin", --Name of group
"superadmin", --Name of acces group in Azarath
"white", -- This command in white list or in black list
{"setPos"} --Commands
)
Help plz to solve problem