[Zope] How to test with isinstance ?

[Jerome Alet]

Hi,

I want to find if an object is an instance of OFS.DTMLDocument.DTMLDocument

How can I do that in an external method ?

It raises an error saying that OFS.DTMLDocument.DTMLDocument is not a class
when I try with isinstance()

I've searched isinstance on ZDP and Zope.org without luck except for 
an email message I haven't understood about extension classes.

please could someone help me ?

thanks in advance

Jerome Alet