Fifo was never created

I have the follow code: ...

umask(0);
unlink(FIFO_FILE);
mknod(FIFO_FILE, S_IFIFO|0666, 0);
printf("Servidor iniciado.nEm modo de espera de mensagensn");


while(1){

    fp = fopen(FIFO_FILE, "r");

my problem is that open never works cause the Fifo's never was created!