MPI problem..

[darkkillerus]

Hi, I installed an MPI in my raspberry pi by following Dr Simon Cox's instruction. I built a c program and compiled using command
gcc -o checkcircuit main.c.
The compiler detected an error at #include <mpi.h>. Said "main.c:1:17: fatal error:mpi.h No such file or directory. Compilation terminated." May I know what's the problem?

[BMS Doug]

please provide a link to the guide/instructions you followed and detail the steps you took.