[Zope] manage_changeProperties Question

[complaw@hal-pc.org]

I need to interate through a set of objects (in this case, DTML Documents) and
set a particular boolean property to FALSE.  I looked at the documentation, and
found something similar in the Zope Book.  However, something must be missing in
the translation, because the following code...

  <dtml-in expr="objectValues('DTML Document')">
     <dtml-call expr="manage_changeProperty(on_host_committee=0)">
  </dtml-in>

.. generates an attribute error, namely:

Zope Error

Zope has encountered an error while publishing this resource.

Error Type: AttributeError
Error Value: manage_changeProperty

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patience.

Traceback (innermost last):
  File /home/zope/Zope-2.4.4-src/lib/python/ZPublisher/Publish.py, line 223, in
publish_module
  File /home/zope/Zope-2.4.4-src/lib/python/ZPublisher/Publish.py, line 187, in
publish
  File /home/zope/Zope-2.4.4-src/lib/python/Zope/__init__.py, line 226, in
zpublisher_exception_hook
    (Object: class)
  File /home/zope/Zope-2.4.4-src/lib/python/ZPublisher/Publish.py, line 171, in
publish
  File /home/zope/Zope-2.4.4-src/lib/python/ZPublisher/mapply.py, line 160, in
mapply
    (Object: do_it)
  File /home/zope/Zope-2.4.4-src/lib/python/ZPublisher/Publish.py, line 112, in
call_object
    (Object: do_it)
  File /home/zope/Zope-2.4.4-src/lib/python/OFS/DTMLMethod.py, line 200, in __call__
    (Object: do_it)
  File /home/zope/Zope-2.4.4-src/lib/python/DocumentTemplate/DT_String.py, line
546, in __call__
    (Object: do_it)
  File /home/zope/Zope-2.4.4-src/lib/python/DocumentTemplate/DT_In.py, line 770,
in renderwob
    (Object: objectValues('DTML Document'))
  File /home/zope/Zope-2.4.4-src/lib/python/DocumentTemplate/DT_Util.py, line
231, in eval
    (Object: _.manage_changeProperty(on_host_committee=0))
    (Info: _)
  File <string>, line 2, in f
  File /home/zope/Zope-2.4.4-src/lib/python/AccessControl/DTML.py, line 101, in
guarded_getattr
    (Object: do_it)
  File /home/zope/Zope-2.4.4-src/lib/python/AccessControl/ZopeGuards.py, line
109, in guarded_getattr
AttributeError: (see above)


There isn't a whole lot of documentation on this subject, but I think there
should be.  Does anyone have a gentle hint as to what I'm aparently missing?

TIA,

Ron