I have read the difference between a parked and an addon domain and I am still not sure how to achieve my goal.

I have two domains; domain1.com and domain1.org. I want both domains to point to the same website and I want the domain the person used to enter the site to continue to appear as the person accesses different pages of the site.

If I understand the documentation correctly a parked domain will in redirect the person to the main domain. So if domain1.com is the main domain and domain1.org is a parked domain, someone typing in domain1.org will be redirected to domain1.com and will see domain1.com as they navigate the site. (Not what I want.)

An addon domain seems to be intended to allow a second domain to point to a subdirectory in my site. For example I could use an addon domain domain1.org to point to domain1.com/some_subdirectory/ Not sure what happenes to the domain address as you surf the site. Again, if I am reading this correctly I believe I can just use the addon domain feature and simply point domain1.org to the root of domain1.com. Is this correct? Will someone entering the site with domain1.org continue to see that domain as the naviagate the site?

If I do this do I also need to add the following line to my site.php file:

define('REDIRECT_TO_BASE_URL', false);

in order for the session to continue to show the domain1.org domain?

I am using concrete5 as my web server.

Thank you.