[LaGrande]

i need to know that what kind of file saving system (aka INI writers) you are using.
The common and simplest and mostly used is dini. here goes the example with dini

pawn Код:

public OnPlayerConnect(playerid)
{
    new str[128];
    new name[MAX_PLAYER_NAME];
    GetPlayerName(playerid, name, sizeof(name));
    format(str, 128, "%s.ini", name);// instead of "%s.txt" locate your own folder to user accounts
    if(dini_Int(str, "Banned")==1)
    {
        SendClientMessage(playerid, 0xFF0000AA, "You are banned from this server");
        Kick(playerid);
    }
    return 1;
}

And add this in your ban command

pawn Код:

dini_IntSet(PlayerFile, "Banned", 1);