help with looping.

how do i loop this back using do/while. i must have it loop back to stating the question if the user types "y" and have it say have a nice day if the user types "n".

#include <stdio.h>
int main(void )
{

int i, is_prime=1;
int num ;

printf("Enter a positive integer greater than 1:", &num);
scanf("%d", &num);
for(i=2; i <= num/2; i++){
if(num%i==0){

is_prime=0;
break;
}
}

if(is_prime==1){
printf("%d is a prime number.\n", num);
}
else{
printf("%d is not a prime number.\n", num);
}

printf("do you wish to continue?[y/n]");

return 0;

}

This should get you started.

Code:

---

int main(void)
{
  char again;

  do {
    [...]
  } while (again == 'y');
  printf("Have a nice day!\n");

  return 0;
}

---