#define NOT_LOGGED_IN 20
#define CMD_NOT_SUPPORTED 30
#define PASSWORD_REQUIRED 40
+#define ALREADY_LOGGED_IN 41
+#define USERNAME_REQUIRED 42
#define HIGHER_ACCESS_REQUIRED 50
#define MAX_SESSIONS_EXCEEDED 51
+#define RESOURCE_BUSY 52
+#define RESOURCE_NOT_OPEN 53
#define NOT_HERE 60
#define INVALID_FLOOR_OPERATION 61
#define NO_SUCH_USER 70
#define ROOM_NOT_FOUND 72
#define NO_SUCH_SYSTEM 73
#define ALREADY_EXISTS 74
+#define MESSAGE_NOT_FOUND 75
#define ASYNC_MSG 900
#define ASYNC_GEXP 01