Simple give ammo hook

How can I do this? I’ve tried like 1000 different ways,when I player says !givemefreeammo I want it to give them unlimited reserve ammo, but they still have to reload.
Thanks for helping, this is for my zombie server.

[lua]
hook.Add(“PlayerSay”, “Ammo”, function(p,t)
if( string.lower(string.sub(t, 1, 15)) == “!givemefreeammo” ) then
p:GiveAmmo(“smg”, 99999999999)
end
end)
[/lua]