EC -

>> I have read the VFP9 help. But it hard to understand. <<

Well, the part you quote describes what you have to do if you want to write your own Preview Container Factory which, admittedly, isn't for beginners. The minimal set of things you have to do in order to get creative with preview is actually very simple.

But, on the whole, I think that you can't have too much in-depth information in the VFP help file...

- Colin