How to validate against duplicate email address

Hi,

I've searched the forums and found postings relating to using validation toolkit to check for duplicate email addresses in a database before adding a new record but I don't fully understand how to get it to work and I was hoping someone could explain it more clearly for me? I've listed the exact steps I need to create below.

1) Check the email address a user enters into a registration form against records in a database

2) If the email address is found in the database then the record is not inserted, instead a message is displayed stating that the email address is already registered

3) If the email address is not found then the record should be inserted into the database.

I know I need to create a recordset that is filtered by email address (check the database values against the value entered into the email field on the form), but I don't know how to specify the validation rule correctly - do I use Like Entry??

Also I should point out that I'm not using DataAssist to generate the insert record code - instead I'm just using Dreamweaver's built-in Insert Record behaviour.

Any help is appreciated.