Forward declaration of struct

Hi all,

I am trying to transfer an old program from CVI 2010 to 2017 and during the process , i encounter this problem.

The program has two .h files :

+ In the first h file , I have below struct:

struct Serie				
  {
  int product;             
  unsigned int prod;
  char type[50];
  char setup[50];
  struct Date date;
  struct Time time;
  double humidity;
  double temperature;
  int coilsInSerie;
  int coilsMeasured;
  int coilsRejected;
  int coilsGood;
  int notInBandgroup;
  struct Parameter value[PARAM_NUM];
  };

+In the second .h file , I include the first .h file and want to use Serie struct as an element of below struct:

struct Setup 
{ 
int ableToMeasure[PARAM_NUM];
int switchPort;
struct Clamp clamp[2];
struct Serie serie[2];
};

  "SETUP.H"(45,21)error: array has incomplete element type 'struct Serie'
 "SETUP.H"(45,10) note: forward declaration of 'struct Serie'

I now know I have to forward declare struct Serie , just i don't know how.

Somehow , the program complied fine in CVI 2010 , any help is appreciated though.