[Knappen]

Was that meant for me or for KING3?

Yeah, you could just a macro for it as well, something like

pawn Код:

#define IsLoggedIn 
            if(pInfo[playerid][LogIn] > 0) return 1;
            else return SendClientMessage(playerid, COLOR_RED, "ERROR: You must be logged in to use this command!");
#endif 
/* Not that used to macros, but I guess this should be here? */