@EventHandler
  public void onEntityDamage(EntityDamageEvent e) {
    if ((e instanceof EntityDamageByEntityEvent)) {
      EntityDamageByEntityEvent event = (EntityDamageByEntityEvent)e;
      if (((event.getDamager() instanceof Player)) && ((event.getEntity() instanceof Player))) {
        Player attacker = (Player)event.getDamager();
        Player player = (Player)event.getEntity();
        Arena arena = this.gm.findArenaByPlayer(player);
        if (arena == null)
          return;
        if (arena.allowTeamkill)
          return;
        PlayerInfo iPlayer = arena.findPlayer(player);
        PlayerInfo iAttacker = arena.findPlayer(attacker);
        if (!iAttacker.team.equals(iPlayer.team))
          return;
        event.setCancelled(true);
      }
    }
  }