Force unique display name

[TheresaBug]

Is there a way to force users to choose a display name that is unique? I know username and email both have to be unique, but we want to do this with display name as well.

We are using the s2member profile shortcode, to allow members to change their display name. However it doesn't force uniqueness.

Which hooks could I call to in order to accomplish this? Any help or ideas are GREATLY appreciated.

[TheresaBug]

We paid for s2member pro, if that makes any difference. Is there some way to integrate this functionality?

I have figured out how to echo values to the profile form, and even getting an alert box to popup when the form is loaded, if the user has a displayname matching any other user.

Just having a hard time know exactly how to trigger the alert when the displayname is edited, or to popup and prevent saving if it's a duplicate displayname.

We are using an embedded chatroom, so this unique display name is crucial to our architecture.

[Cristián Lávaque]

Well, the only things checked for uniqueness are the username and the email address. You could use the username as the display name. Would that work for you?

Otherwise, you'll need to customize your installation. You could fine a freelance developer in websites like oDesk.com or eLance.com.

I hope that helps.