Websites redirects


I’ve created a new virtual host to create a new web site
This domain is not registered yet.
To work on it and allow the owner to see previews I created an ‘alias to directory’ redirect -> /home/NEWdomain/public_html

Going to my browser displays a Forbidden warning.
When I create an index.html the browser opens the page as expected but when I substitute index.html by index.php a window "You have chosen to open: (blank here)… which is a phtml file…Open? Save? ".

I guess this is a security issue about php-cgi and owners.

How can I handle that?

Thank you

Anybody to help?