[Correlli]

pawn Код:

public OnPlayerRequestSpawn(playerid)
{
if(!_PLAYER_AUTHED_[playerid])
{
SendClientMessage(playerid, _YOUR_COLOR_, "You need to login before you can spawn!");
return 0;
}
return 1;
}

I hope this helps you.
You'll need to define your own _PLAYER_AUTHED_ and _YOUR_COLOR_.