Okay, assuming that you are using PHP, then the error is probably opening the file with the wrong permissions, assuming that your instructor is not stupid.
First, eliminate the possibility that your instructor is a stupid, with this:
//replace the filenme here with what he told you to copy
if(is_readable("/home/instructor/file.txt"))
echo "my instructer is smart";
else
echo "he is a tard";
if this output's that your instructer is smart, than go:
$file = fopen("/home/instructoer/file.txt", r);
the part you were probably missing was the 'r', this tells the computer that you only want to read his file, not write over it.
