Problems regarding cron

[webstars]

I had setup cron for phpadsnew. But whenever i checkup my cron logs, i see an error for it saying

/bin/sh: /home/webstars/domains/smokyhosts.com/public_html/ads/maintenance/maintenance.php: Permission denied

Why is it so, and how can i rectify it? Please help.

 

[RichardF]

I have a cron for phpadsnew like
wget -q -O /dev/null http://www.domainname.ext/maintenance/maintenance.php

I do not get an error .. at my server it seems it doesn't work at all.