Update readdata.h

readdata.h

@@ -31,6 +31,7 @@ typedef struct{
 	
 }users;
 
+int CheckLetters(char word[STR_MAX]);
 void NewTicket(int *row, int *col, char *seat, int flightID, MYSQL *con, int count);
 int CheckUser(MYSQL *con, char *username, char *password);
 MYSQL* connectToMySQLServer();