Review my code

I'm trying to do problem 4 on Project Euler but something isn't going well.
If you could review my code to tell me what I'm doing wrong.
http://pastebin.ca/1956037

EXPERT C SOLUTION

//  pipe output through sort -n

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

int ispalindrome(char *s) {
  char *sr,*p,*pr;
  int r;
  sr = strdup(s);
  pr = sr + strlen(s);
  *pr-- = 0;
  for(p=s;*p;p++,pr--)
    *pr = *p;
  r = strcmp(s,sr);
  free(sr);
  return !r;
}

int main() {
  int x,y;
  char s[64];
  for(x=999;x;x--) {
    for(y=999;y;y--) {
      sprintf(s,"%d",x*y);
      if(ispalindrome(s))
        printf("%s\n",s);
    }
  }
  return 0;
}