I would like to add a custom field to the RegistrationForm webpart.

I have read the V3.x article on this (http://devnet.kentico.com/Knowledge-Base/Web-parts---Controls/Adding-custom-fields-into-RegistrationForm-web-par.aspx). However, it appears that in V4.x the procedure to save data to the database will be slightly different.

For example, in the code behind, I can see a UserInfo object being created to hold the form data

Line 551
ui = new UserInfo();
ui.PreferredCultureCode = "";
ui.Email = txtEmail.Text.Trim();
ui.FirstName = txtFirstName.Text.Trim();
ui.FullName = txtFirstName.Text.Trim() + " " + txtLastName.Text.Trim();
ui.LastName = txtLastName.Text.Trim();

etc

If the correct approach is to add a custom field for my data (through CMSSiteManager -> System Tables -> User ), then how do I include my custom data in the UserInfo object so that it is saved?

Also, would it be worth creating a new Knowledge Base article for V4.x outlining the whole procedure?

Thanks

Steve