new Symbol;
new PlayerName[MAX_PLAYER_NAME+1];
GetPlayerName(playerid, PlayerName, sizeof(PlayerName));
if(PlayerName[0] < 'A' || PlayerName[0] > 'Z') return Kick(playerid);
for(new A = 1; A < strlen(PlayerName); A++)
{
    if(PlayerName [A]== '_')
    {
        if(Symbol == 1 || PlayerName[A+1] < 'A' || PlayerName[A+1] > 'Z') return Kick(playerid);
        Symbol = 1;
        A += 2;
        continue;
    }
    if(PlayerName [A]< 'a' || PlayerName [A]> 'z') return Kick(playerid);
}
if(!Symbol) return Kick(playerid);