webpage->cgi->fopen

I am using C to write a cgi that get data from a dhtml page and store them in a text file. However, the text file == NULL after I run the fopen command. I have run the sourceCode under the Unix shell and the source is oaky. (It write and safe files)

this is my source in the c program:


#include<stdio.h>
#include<stdlib.h>
#include<string.h>
FILE *outfile;

...

outfile = fopen("register.txt", "w");
if(outfile==NULL){
printf("An error has occured.\n");
return 1;
}

fprintf(outfile, "Date registered:");
fclose(outfile);
...

Anything I have done wrong? Thanks.

Simple Question:
Has the user who is running the webserver write access to the directory where your cgi-skript is running?