Thanks!
I must confess, I am unix illiterate. I don't know any more about chgrp or chmod than can be found in the PHP manual. I don't know how to identify what group my webserver is in (It's being hosted by Cedant). So now I'm using this code:
chgrp("$userfile[$i]","nobody");
chmod("$userfile[$i]",0770);
And in addition to the previous error, I'm getting this error:
Warning: chgrp failed: Operation not permitted in /home/domain/domain-www/submissions/marketing.php on line 20
Again, I'd appreciate any help