You want the userlevel field to be a hidden type. This allows you to process the field normally but keeps the user from seeing the field or modifying it.
One tip. It is far easier to learn how these extensions work if you don't hold on to pages that go astray. Just delete the page and try again. Every time you try something, study the generated code. You will quickly learn what happens with different options. If you keep reusing the same page you can end up with duplicate code that can mess things up and make it hard to figure out.
Concentrate on learning the extension instead of a successful outcome. That way you will understand what's going on instead of just completing a page.
