How to let 2 domains show the same contents in Hostgator Hosting?

Sometimes we want to 2 domains show the same contents in Hostgator Web Hosting, and show different domain. For example, we want to let www.cheapglasses123.com, and www.bestpriceglasses.org show the same contents, but use differnt domains also. We can do like this when we Addon Domains to Hostgator Cpanel.

cheapglasses123.com

New Domain Name: cheapglasses123.com 
Subdomain/Ftp Username: cheapglasses123 
Document Root: / public_html/cheapglasses123.com
 

bestpriceglasses.org

New Domain Name: bestpriceglasses.org
Subdomain/Ftp Username: bestpriceglasses
Document Root: / public_html/cheapglasses123.com

King Php Science Welcome, you are from: 54.80.140.5