File open dialog box

Hi everybody, I'm trying to write a code that provide a dialog box for selecting multiple files and renaming all of them to change their extensions. Can anybody help me how can i do it?



Thanks in advance

Your question involves solving multiple problems in multiple steps, and so before we write a complete multi-page tutorial, let's save us all some needless effort and find out exactly what you have done so far, and what *specific* step you may be stuck on.

Here is an example: Show open dialog