Error in my code, help?

http://www.megaupload.com/?d=LWV4LGD5

is the link to my files, but it does not output right, when u do the input file it tries to make you save another file, makes no sence. Would be great if someone can spot the error.

Thanks heaps

What language is this?  The dollars look like Perl, but fopen/fwrite/fclose are C?

Oh, and your comment is misleading.  The file is CAf.txt, lots of filesystems are case-sensitive.