I've got a FileListBox in which I'm displaying all the files in a directory. I'd like to allow the user to filter files based on the existing (displayed) file exentensions. I've succeeded in doing this but it's very slow on directories with a lot of files. Basically I've populated a dynamic array with all extensions then pull one out, cycle through looking for duplicates, then go to the next one. I then add the unique extensions to a Combo Box. I know there's got to be a better and faster way. Any help is much appreciated! Thanks!