Executing CRON from a WebForm..

Hi!!. I'm trying to give users the chance to modify its cron from a webform. The webform let's the users choose the day, month and minutes after hour, then, using PHP I made one long string and save it into a file ($tmpnam), it looks like this: $content = "$min $hour $day * * /tmp/parse_maillog.sh"; //I obtain $min $hour & $day earlier in my webform $tmpfname = tempnam ("/tmp/mail", "$username_crontab.txt"); $handle = fopen($tmpfname, "w"); fwrite($handle, $content); fclose($handle); system("crontab -u $username $username_crontab.txt"); unlink($tmpfname); Debugging this part I found that the file is OK, the problem is with the "system" function, obviously a "user" problem, how can I fix it?? any ideas?? I use phpSecurePages as an authentication system. Thanx.. -- The explanation requiring the fewest assumptions is the most likely to be correct. -- William of Occam