Registration system

I have a private form that captures name, address etc. When someone goes to the form the standard Zoho Sign In form is displayed. This is exactly what I want. However if they don't have a Zoho account there is no option to create an account. How do I get a sign up button to show?

I expect about 1500 people to register and I want each to have a separate ID.

To add a little complexity I want to avoid displaying the Zoho logo. Zoho is a great brand but some people will get confused.

Herb Wexler MBA