Replacements for IsValidIID and IsValidInterface

From: David Liebtag (DavidLiebtag_at_vermontel.net)
Date: 01/10/05 

Date: Mon, 10 Jan 2005 14:12:47 -0500

There used to be functions names IsValidIID and IsValidInterface. They are
now obsolete.

Can anyone suggest what I can use as a replacement to validate whether an
arbitrary value is an interface?

Thank you.

David Liebtag