[Zope] attribute error: absolute_url

[wazum-mail (wolfgang)]

Hiya!

I have a folder /home
with the standard_html_header (DTML method)

this line should include a stylesheet definition if available in a
(sub)folder ...
<dtml-if text_css_styles><link rel="stylesheet" type="text/css"
href="<dtml-var "text_css_styles.absolute_url ()">"></dtml-if>

but when I call it from a subfolder where the text_css_styles DTML Document
exists
I get this error message:

Traceback (innermost last):
  File /usr/local/Zope-2.3.2/lib/python/ZPublisher/Publish.py, line 223, in
publish_module
  File /usr/local/Zope-2.3.2/lib/python/ZPublisher/Publish.py, line 187, in
publish
  File /usr/local/Zope-2.3.2/lib/python/Zope/__init__.py, line 221, in
zpublisher_exception_hook
    (Object: Traversable)
  File /usr/local/Zope-2.3.2/lib/python/ZPublisher/Publish.py, line 171, in
publish
  File /usr/local/Zope-2.3.2/lib/python/ZPublisher/mapply.py, line 160, in
mapply
    (Object: index_html)
  File /usr/local/Zope-2.3.2/lib/python/ZPublisher/Publish.py, line 112, in
call_object
    (Object: index_html)
  File /usr/local/Zope-2.3.2/lib/python/OFS/DTMLDocument.py, line 189, in
__call__
    (Object: index_html)
  File /usr/local/Zope-2.3.2/lib/python/DocumentTemplate/DT_String.py, line
538, in __call__
    (Object: index_html)
  File /usr/local/Zope-2.3.2/lib/python/OFS/DTMLMethod.py, line 182, in
__call__
    (Object: standard_html_header)
  File /usr/local/Zope-2.3.2/lib/python/DocumentTemplate/DT_String.py, line
538, in __call__
    (Object: standard_html_header)
  File /usr/local/Zope-2.3.2/lib/python/DocumentTemplate/DT_Util.py, line
334, in eval
    (Object: text_css_styles.absolute_url ())
    (Info: text_css_styles)
  File <string>, line 0, in ?
  File /usr/local/Zope-2.3.2/lib/python/DocumentTemplate/DT_Util.py, line
127, in careful_getattr
AttributeError: absolute_url


Zope Information:

Zope Version  Zope 2.3.2 (source release, python 1.5.2, linux2)
Python Version  2.0 (#2, Jun 14 2001, 17:54:01) [GCC 2.95.3 20010125
(prerelease)]
System Platform  openbsd2


Any suggestions?

tia
Wolfgang