Thanks Dmitry
1) method document_src() requires no parameters (self is passed implicitly by python) so you write context.['index_html'].write(context.memberIndex.document_src())
I tried this and got the error message mentioned, so I tried again with the explicit 'self' - no go.
2) To create a page template with a content, you may pass it in constructor: container.manage_addProduct['PageTemplates'],manage_addPageTemplaate('index_html', text=context.memberIndex.document_src())
This is certainly more elegant and I had spotted it in ZopePageTemplates.py but I wanted to go step by step. However, neither of the solutions works for me because I always get the 'Unauthorized' error message. With my limited experience, I don't know how to start debugging this. Can you help me again? regards Richard