#define AUTH_GOOD 1
#define AUTH_BAD -1
-#define AUTH_NO_MONEY -2
+#define AUTH_NO_MONEY -2 /* for balances < $0 */
#define AUTH_LOCKED -3
+#define CREDIT_OK 1
+#define CREDIT_FAIL -1
+
+#define REQUEST_OK 1
+#define REQUEST_NO_MONEY -1 /* insufficient credit */
+#define REQUEST_SERVFAIL -2 /* server did not respond */
+#define REQUEST_EMPTY -3 /* none of item left */
+#define REQUEST_INVAL -4 /* no such item */
+
u8 server_authenticate(u16 uid, u16 pin);
#endif /* _SERVER_H_ */