account activation email

Thank you very much for your reply to my question. I have a more specific question in regards to your response, in particular steps 6 and 7 or your method. I would like to send the user an email containing a link that contains: 1. their email address 2. a string created by the CreateUUID() function or another random string creation function attached to the URL as variables. So, the email that I send will look something like the following:
www.mypage.com/regconfirm.cfm?email=useremail.com&registrationnumber=CF123254323245325452454235324
When the user clicks on this, it would submit the variables email and registration number to this page, confirming and finishing the registration cycle. Is there any problem with this approach? Thanks so much! dan

Basically, the steps are these:

1. The form should have a unique user identifier, such as an e-mail address or SSN.
2. The user completes the form and clicks "Submit".
3. Either client-side (JavaScript) or server-side (ColdFusion) validates the form.
4. If the form is valid and the user has not already registered, update the database with the user's information
5. The update should contain a unique value, such as an auto-id.
6. An e-mail is sent to the user that contains a link to a login page at the site and the unique id value.
7. The user clicks the link in the e-mail, enters the unique id into the login form and clicks "Submit".
8. The record containing the unique id is retrieved from the database.
9. The user now has the run of the site.