Error while doing server client using pipes..... plzzz help ??

Hi,
I am new to c++ programming.... i am working on a example and when ever i run the following code i get error "Server fifo failure" this is an example and should work alright but error making no sense... :(
I am running this code using sun C++ compiler....

Plzzzz help....

#include "common.h"
#include <ctype.h>

int main()
{
int server_fifo_fd, client_fifo_fd;
struct data_to_pass_st my_data;
int read_res;
char client_fifo[256];
char *tmp_char_ptr;
mkfifo(SERVER_FIFO_NAME, 0777);
server_fifo_fd = open(SERVER_FIFO_NAME, O_RDONLY);
if (server_fifo_fd == -1) {
fprintf(stderr, "Server fifo failure\n");
exit(EXIT_FAILURE);
}

sleep(10); /* lets clients queue for demo purposes */
do {
read_res = read(server_fifo_fd, &my_data, sizeof(my_data));
if (read_res > 0) {
tmp_char_ptr = my_data.some_data;
while (*tmp_char_ptr) {
*tmp_char_ptr = toupper(*tmp_char_ptr);
tmp_char_ptr++;
}
sprintf(client_fifo, CLIENT_FIFO_NAME, my_data.client_pid);
client_fifo_fd = open(client_fifo, O_WRONLY);
if (client_fifo_fd != -1) {
write(client_fifo_fd, &my_data, sizeof(my_data));
close(client_fifo_fd);
}
}
} while (read_res > 0);
close(server_fifo_fd);
unlink(SERVER_FIFO_NAME);
exit(EXIT_SUCCESS);
}