API Remove Dupes from ListBox

This is in response to many requests for "removing duplicates in a listbox" in the discussion forum. Using the API is almost always faster than using VB. I'm unaware of any examples here on PSC of using the API for removing dupes - I may be wrong. Either way this is a very efficient way of accomplishing this task. No need to vote - code couldn't be much simpler than this! Feel free to improve upon the code yourself. As usual all bugs come entirely free of charge.