Adding another Domain Name to be fully hosted

I am wanting to add another Domain Name to be Fully Hosted by DreamHost.
I went to the screen that says “Manage Domains”.
At the bottom of that screen I clicked on “Add a New Domain”.
I got a screen that says "Please choose the kind of hosting you would like to add:"
I typed in my Domain name… (MYNEWDOMAIN.COM)
I clicked on the bar that says "Fully host this domain now"
HOWEVER, …I get an ERROR message that says "Un oh! Please fix the error below: "Invalid domain: domain name must end with a letter or number."
I don’t understand ? ? ? What am I doing wrong ? ? ?

ok… I just tried again.
This time I typed my domain name in lower case instead of all upper case letters (
Now I get an ERROR message for the Web Directory I had left blank.
It says Web Directory: /home/username/ [ Blank space ] /
Required (can only be alpha-numerics)
I don’t understand what goes there so I left it blank ? ? ? ?
What does go there anyway ???

Well,… it must have been a glitz with the panel because I cleared my cache and tried again with a fresh start and this time it went though like a breeze. Easy as ABC…