diff --git a/src/currencyExchange.h b/src/currencyExchange.h
index fe80c35..6629fcc 100644
--- a/src/currencyExchange.h
+++ b/src/currencyExchange.h
@@ -1,7 +1,9 @@
 #include <stdio.h>
 
-#define CURRENT_USD_RATE_OF_ONE_EURO 1.07
-#define CURRENT_GBP_RATE_OF_ONE_EURO 0.89
+#define USD_RATE_OF_ONE_EURO 1.07
+#define GBP_RATE_OF_ONE_EURO 0.89
 
-float toUSD(float euro);
-float toGBP(float euro);
\ No newline at end of file
+#define CURRENCY_CODE_USD 1
+#define CURRENCY_CODE_GBP 2
+
+float convert(float euro, int newCurrencyCode);
\ No newline at end of file