What exactly do you mean by "new Page B class ... with a class B1?" Do you mean that Page B has a B1 as in a one-to-one database relationship?

How all this will work for you will depend on the actual names of your classes. You need to do a ?flush=1 once you've added your classes, of course. You also need to make sure the autoloader, with the help of the manifest builder, is going to find your classes. I'm no expert on exactly what will and won't be found, but note this from the manifest builder documentation:

"If your class contains an underscore, for example, Page_Controller, then the filename is expected to be the stuff before the underscore. In this case, Page.php.''

Toby

Yes, I think you should try moving B1 and B2 out into their own files (B1.php and B2.php).

Classes in MyFile.php should be just MyFile and MyFile_*.

And regarding your resolution:

"If you don't know why it works it probably doesn't -- you just don't know it yet"
- Steve McConnell, "Code Complete"

Toby

I had resolved with your tip ...

class Product_ResizeImage extends Image into product.php file

and

class SpecialDataPage_BannerImage extends Image into SpecialDataPage.php file.

Thanks...