[Beowulf] error while using mpirun

[akshar bhosale]

i have installed mpich 1.2 6 on my desktop (core 2 duo)

my test file is :

#include<stdio.h>
#include<mpi.h>

int main(int argc,char *argv[])
{
        int rank=0;

        MPI_Init(&argc,&argv);

        MPI_Comm_rank(MPI_COMM_WORLD,&rank);
        printf("my second program rank is %d \n",rank);

        MPI_Finalize();
        return;
}

---------
when i do
/usr/local/mpich-1.2.6/bin/mpicc -o test test.c ,i get test ;but when i do
/usr/local/mpich-1.2.6/bin/mpirun -np 4 test,i get

p0_31341:  p4_error: Path to program is invalid while starting
/home/npsf/last with rsh on dragon: -1
    p4_error: latest msg from perror: No such file or directory
error.
please suggest the solution.