Setting an Existing Form/Page as Dynamic

I am implementing a Paid Membership into a custom database. I have an Membership input form with the PayPal “Buy It Now” button implemented. The entries on the form are successfully stored in a database. I have also implemented the member profile page as outlined in the article:

For the Update My Profile portion of this article I have duplicated the Membership form, less the Pay Pal info so the logged in user can update their profile. When I select the duplicated page, it shows that the fields in the form are indeed connected to the items in the database. In order to use this for the Profile Update I needed to change the page to a Dynamic Page so I clicked on “settings” for the page and selected Item Page and clicked Next. I added “email” to the URL but the only option is to Create Page? The page already exists? What do I do? Can I NOT use and existing page?

Thanks
JD

Nevermind. I simply clicked on Create and it INDEED changed the page and it now shows up in the Dynamic Pages section of the Pages Menu.
JD