public OnPluginStart()
{    
          AddCommandListener(ChooseTeam, "jointeam");
}

public Action:ChooseTeam(client, const String:command[], args)         
{     
          if (client < 1 || args < 1) return Plugin_Handled;     
          decl String:teamString[3];      
          GetCmdArg(1, teamString, sizeof(teamString));      
          new Team = StringToInt(teamString);     
          if(Team > 1) CheckAllAlive(client);
}    

CheckAllAlive(client)
{
         for (new i = 1; i <= MaxClients; i++)
         {
               if(IsClientInGame(i) && GetClientTeam(i) > 1 && IsPlayerAlive(i)) return;
         }
         ServerCommand("mp_restartgame 1");
}