go to your cpanel, look at Stats -> Home Directory,
where you can see your username
scroll down to Advanced -> click on Cron jobs
under "add new cron job" click on "minute" -> every five minutes (*/5)
Command:
/usr/bin/php -f /home/your_username/www/cron.php >/dev/null 2>&1
which should work fine.
you can do a test write every 5 minutes, for example
cron.php:
PHP Code:
<?php
$content = ".";
$f = fopen ("/home/your_username/www/scores.txt", "a+");
fwrite($f,$content,strlen($content));
fclose($f);
?>
(remember to create cron.php in your document root)
open "scores.txt" in your browser to see if it works,
there should be an dot added every five minutes..