>The problem is that I need to wait until the compression is complete before I do any
>processing of the finished compressed PDF file.
>
>SHellExecute is not modal and I need to wait for it to finish before processing the
>result. ShellExecute returns a window handle. I tried using the API IsWindow(Handle)
>but it always returns 0.
>
>Does anyone know how to ask the question: Is the external process finished?

John, I know it's a little late, but here's some VB code that answers that question nicely. Shouldn't be too hard to convert.

http://www.experts-exchange.com/Programming/Programming_Languages/Visual_Basic/Q_21418540.html