I've changed the A record for www.fshsanantonio.com

Hello,
I've changed the A record for http://www.fshsanantonio.com to point to 107.180.3.177, which is where the plugin is installed. The multisite is http://www.foundationhospitals.com and the particular site I want http://www.fshsanantonio.com to point to is http://www.foundationhospitals.com/sanantonio. However, I get "The domain name is unavailable to access." Am I missing a step?

Thank you