Filter and poupulate the data in 2 combo boxes

This is a very common problem, there must be hundreds of articles on the web on how to do this, as well as being somethign that is thoroughly covered in every ASP.NET book every printed. Have you bothered looking for articles on this ? Bothered to buy a book and read it ?

There is no way the code to do this would even fit in a forum reply. Forums are best for programmers who try to do their own work, but find they need specific help.