compiling parallel hdf5 file help!

i have one question with compiling hdf5 file. i can compile the non-parallel
hdf5 file with
module load hdf5-gcc/3.4.6

module load mpich-intel
h5cc simple.c >> work fine for normal hdf5 file(non-parallel)
if i include MPI-related code ,it failed.

Error:
'MPI_Comm' undeclared (first use in this function)

//////////////////simple.c /////////////////////
#include "hdf5.h"
#ifndef MPI_FILE_NULL
#include <mpio.h>
#endif
#define H5FILE_NAME "SDS_row.h5"
int main(int argc,char **argv)
{
   hid_t file_id;
   hid_t plist_id;
   herr_t status;
   int mpi_size,mpi_rank;
   MPI_Comm comm = MPI_COMM_WORLD;
   MPI_Info info = MPI_INFO_NULL;

}

thanks
winthan