OK, now I have a real question: on my machine, I try the following.... %man random and get a bunch of stuff about a random number generator. .... SYNOPSIS #include <stdlib.h> long int random(void); void srandom(unsigned int seed); char *initstate(unsigned int seed, char *state, size_t n); char *setstate(char *state); .... CONFORMING TO BSD 4.3 ...... So, ignoring this, I use the following in a random number generator program and get the following while compilation.... gcc -c -O3 -std=c99 -Wall -pedantic random.c random.c: In function 'setseed': random.c:35: warning: implicit declaration of function 'srandom' random.c: In function 'runi': random.c:48: warning: implicit declaration of function 'random' But I have included stdlib.h so what is the problem? Many thanks and best wishes, __________________________________ Yahoo! FareChase: Search multiple travel sites in one click. http://farechase.yahoo.com