Define Pages Editor Permission

Hi,

I've searched everywhere for an answer to my problem. I'm trying to change the content on the main page of my site https://www.rosalealilycosmetics.com/store i.e. the bit where it says Have you got yours yet?.

I believe this is done through admin-tools-define pages editor. I've tried changing it but I get the following error message.

Forbidden
You don't have permission to access /store/admin/define_pages_editor.php on this server.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

Apache/2.2.14 (Unix) mod_ssl/2.2.14 OpenSSL/0.9.8e-fips-rhel5 mod_auth_passthrough/2.1 mod_bwlimited/1.4 FrontPage/5.0.2.2635 Server at https://www.rosalealilycosmetics.com Port 80

I've tried changing the permssions to this file to 777 and 755 but its still not working.

Has anyone any ideas for me please????

Thanks,

Liz

OK. A small update. I am able to edit define_main_page.php in html_includes/mytemplate but I'm still not able to do it using the Zen Cart admin area.