Validate Group Code During Registration

We are allowing users to register online. We want them to enter their special group number so we can limit their access to only data within that group. We do not want to do a dropdown list becuase we do not what to expose the group codes. We have a user table and a group table. The group table has the codes for the groups. The user has the user information, including a field for the group that they beloing to. How do we validate that the group number they entered in the registration form is an active code in teh groups table?

In Dreamweaver create a record set for the group table and add a filter which compares the group number to the value entered in the form.

And if you wanted to add some text to show when the group number is invalid then Select the text and use the Dreamweaver Show Region server behavior by clicking the + button under the Server Behaviors panel (Window -> Server Behaviors) and select show region "Show if Record Set is Empty" and select the group record set. And then you will need to wrap the insert server behavior with the same condition, so it does not insert to the database if the group record set is empty.