[OMPI users] Migrating from MPICH-1.2.6 to OpenMPI-1.2.7

[Shafagh Jafer]

Hello,
I want to know if I need to make any modifications to my source code to replace 
MPICH-1.2.6 with Openmpi-1.2.7?? I mean are the function interfaces exactly the 
same in both MPISH and OMPI?? please let me know. 
Thanks.