[Zope] calling zpt from a script with options

[Haim Ashkenazi]

Hi

forgive me if it's trivial, but I'm a complete zope newbie....

I read in the zope book that if I want to call zpt from a script (in my
case, to render errors in a form) I do something like this:

--
script:

pt = context.body_content
s = pt(zerror="This is an error")
return s

zpt:

<i tal:content="options/zerror | default">error</i>
--

This works without a problem, but it only shows the "body_content" file.
this file is part of a layout (inside a folder) and I want to call the
folder as the url, so it will acquire the index_html in an upper directory.

I tried changing the "pt" variable to context.index_html and calling
"here/index_html/options/zerror" in the template but it didn't show. 

how can I achieve that?

thanx
-- 
Haim