Can I use an external Account Number as customer username, instead of email?

Hi

I have an instance where customers already have an unique account/customer number elsewhere in another manual system.

Now they want Zencart to handle their buying etc but they want same customers to be added with their existing 'customer account numbers'. Using the DrByte's code here is fine but is there anyway that this customer account number can be added rather than auto generated and basically assigned manually by admin then it would show on their purchases and correspondence, welcome email etc.?

Hi

In my case customers have already their 'Account/Customer Number' with the company . Company now going online and they would like to use their existing 'Account/Customer Numbers' in their system as user name when customers are creating their online accounts.

Currently Zencart uses email address as the user.

Is there a way that.

1. Adding a new field as 'Account/Customer Number: ' when they register

so that also can be varified as

1. 'if Account/Customer Number exists and correct'

2. 'if email exists and correct '

3. 'if password exists and correct '
   = LOGIN > if not = LOGOUT

4. 'if Account/Customer Number does NOT exists and it is NEW'

5. 'if email does NOT exists and it is NEW'

6. 'if password does NOT exists and it is NEW'
   = REGISTER

how else can I do this?

To clarify, you're asking how to let them use "either the account number or their email address" to login to their account (instead of just email address), right?