Help-Quick question on hostgator hosting.

Ok i bought a domain from namecheap and want to add on domain to my hostgator account.

Currently i have 1 domain name bought from namecheap as well and already running on hostagator name server.

Now I already bought another domain from name cheap and during checkout already configured the dns name server to hostgators'( The same from the previous one right?)

When i choose to add on domain. under Subdomain/FTP Username
it gives me this "That is not a valid Subdomain/FTP username".The document root is fine.Is this normal? Is it because Im using an entirely new domain as compared to a subdomain? Or is my domain too long? How do i fix this?

I dont want to mess up my previous website.Am i doing it right?

Thanks a lot

I think you need to wait for a while for hostgator to propagate the dns

Just change the username to what you want. It's probably just pre filling in the domain name as the FTP username. It will have a length limit.