Issues with EDIT page

I have uploaded the following:
http://demo.asprunner.net/lisaham2006%5Fya...sup28/login.php
This is what suppose to happen:

User register and logs in. [suppliers table]

User then enters there company info, name, telephone, etc via the edit page [suppliers table]

Informations is populated to the supplier_info table. [email being the primary & foreign keys]

User can hover and see the populated info via the link on the LIST page.

User can click link and edit info on supplier_info table.
All works fine when EDIT email field is ticked on the supplier table at choose fields section.
This is the problem

I do not want the registered user to be able to edit there email address via the EDIT page. When i uncheck the EDIT email field via supplier table choose fields, the email address is lost and there no association to build the supplier_info table.
Your urgent help would be most appreciated
Lisa