Size of folder

If there are 10 files of same extension.In run time there is change in no of file how to get size of all files and sum it up as we dosent know the names of file.For vc++ dialog based application.give a sample code if possible

I want to burn the data in DVD using the inbuit software in windows xp operating system.How to do it. I want to do in vc++ dialog based application.

How to get foder size? eg:there is a folder "new" in c:\\ i want to get size of this folder how to get this in VC++ dialog based application.