I am wanting to have the following:

First Name
Last Name
Domain Name

And all of them being "required"

So I removed the others added Domain name.

My Question is how do I make the domain name required and also how do I remove the other attributes (phone number and address) without causing errors.

Right Now I am getting this error when I submit the billing form:

Fatal error: Call to a member function validateAttributeForm() on a non-object in /home/phasabor/public_html/easyprojects/packages/core_commerce/controllers/checkout/billing.php on line 53