cannot run OPENMP in C language using UBUNTU 12.04

[tollyfather]

Below is my code
# include <stdlib.h>
# include <stdio.h>
# include <omp.h>
main(){
int i,k,j,a[100][100],b[100][100],c[100][100];
int nthreads,maxt,procs,tid,inpar,n;
for(i=0;i<100;i++){
for(j=0;j<100;j++){
a[i][j]=rand()%10;
b[i][j]=rand()%10;
}
}
printf("\n MATRIX A\n\n");
for(i=0;i<100;i++){
for(j=0;j<100;j++){
printf("%d \t",a[i][j]);

}
printf("\n");
}
printf("\n MATRIX B\n\n");

for(i=0;i<100;i++){
for(j=0;j<100;j++){
printf("%d \t",b[i][j]);

}
printf("\n");
}
printf("\nENTER THE NUMBER OF THREAD U WANT TO USE:");
scanf("%d",&n);
printf("\nMULTIPLICATION OF MATRIX A & MATRIX B\n\n");
#pragma omp parallel private(nthread,tid,i,j,k){
omp_set_num_threads(n) ;
/* Obtain thread number */
tid= omp_get_thread_num();
/* Only master thread does this */

printf("Thread %d getting environment info...\n", tid);
/* Get environment information */
procs = omp_get_num_procs();
nthreads = omp_get_num_threads();
maxt = omp_get_max_threads();
inpar = omp_in_parallel();
/* Print environment information */
printf("Number of processors = %d\n", procs);
printf("Number of threads = %d\n", nthreads);
printf("Max threads = %d\n", maxt);
printf("In parallel? = %d\n", inpar);



for(i=0;i<100;i++){
for(j=0;j<100;j++){
for (k=0;k<100;k++){
c[i][j]=a[i][k]*b[k][j];
}
}
}
printf("\n");


for( i=0;i<100;i++){
for(j=0;j<100;j++){
printf("%d\t",c[i][j]);
}
printf("\n");
}
}



EACH TIME I TRY RUNNING IT THE ERROR MESSAGE I KEEP GETTING IS BELOW:
/tmp/ccKib029.o: In function `main':
phundred.c:(.text+0x20a): undefined reference to `omp_set_num_threads'
phundred.c:(.text+0x20f): undefined reference to `omp_get_thread_num'
phundred.c:(.text+0x233): undefined reference to `omp_get_num_procs'
phundred.c:(.text+0x23f): undefined reference to `omp_get_num_threads'
phundred.c:(.text+0x24b): undefined reference to `omp_get_max_threads'
phundred.c:(.text+0x257): undefined reference to `omp_in_parallel'
collect2: ld returned 1 exit status


what do i DO?

[oldos2er]

Closed, duplicate of http://ubuntuforums.org/showthread.php?t=214872
Please don't create duplicate threads, it dilutes the community's effort to help you.