hey keep getting the 'attempt to index global 'GM (a nil value)' error...

[CertifiedCode]

Hey I know this is a noob question but keep getting the 'GM' a nil value error using this i basically need to change a playermodel for a specific steam id... this code is from another thread i just tried, i have made my own script for it but it gives me the same error.

function GM:PlayerSetModel(ply)
 
    local mdl = GAMEMODE.playermodel or "models/player/phoenix.mdl";
    if ply:SteamID() == "STEAM_0:0:77876823" then
        mdl = "models/player/alyx.mdl";
    end
    util.PrecacheModel(mdl)
    ply:SetModel(mdl)
end

[manolis]

Change GM to GAMEMODE if you're working in a gamemode

[CertifiedCode]

[QUOTE=Coffeee;47859430]Change GM to GAMEMODE if you're working in a gamemode[/QUOTE]

Ughh hey I just got the error attempt to index global 'GAMEMODE' (a nil value) similar error btw not working on a gamemode

[editline]2nd June 2015[/editline]

K im just going to close thread cause i seem to do is rate me dumb for not knowing stuff thanks anyways! for trying.