how to create a file... for example
file.txt (can it be empty???) (if not write sth to it)
http://www.php.net/manual/en/function.fopen.php
http://www.php.net/manual/en/function.fwrite.php
There many file functions under the Filesystem section of the PHP manual.
$filename= your file; fp = fopen($filename,X);
X = R or W or A
Dont forget to close it after with: fclose($fp);