[Lordzy]

pawn Code:

COMMAND:help(playerid, params[])
{
        new message[128];
        if (!sscanf(params, "s[128]",message))
        new name[MAX_PLAYER_NAME];
        GetPlayerName(playerid, name, sizeof (name));
        format(message, sizeof(message), "%s asks: %s", name, message);
        HelpRequest(-1, message);
        return 1;
}

You must increase the string size first of all and also implement the size on sscanf "s" specifier.