Question about FileChooser

[dougf people net au]

Hi all

I am using a FileChooserDialog to save a file and have set it to confirm overwrite.  My application is saving .wav files but I don't want the user to have to append the ..wav extension. (I am also using a FileFilter *.wav).  After the user has entered the filename I add the .wav extension if the user hasn't (as they never do) but in so doing defeat the overwrite protection and so end users are unknowingly writing over the top of existing files.  I can do such a check externally to the FileChooserDialog but I was wondering if there is a better way?  With the *.wav filter in place I would have expected the dialog to make the assumption that it should itself append .wav to the file - or is that an option that I have missed.  I figured that the functionality I want would be a fairly common design so am asking the question.

Thanks
Doug