[Zope] Problem with parameter submission to Python Scripts

Hi, I'm trying to get the following script to work in zope: for image in context.objectValues('Image'): if not image.hasProperty('original_id'): context.outputdir.makeThumbnail(image.getId()) Where outputdir is a parameter passed to script, and is called with makeThumbnails?outputdir=thumbnail where thumbnail is a folder in Zope. The problem is: context.outputdir.makeThumbnail(image.getId()) I need the object that is refered to by outputdir. For instance if I use: context.thumbnail.makeThumbnail(image.getId()) it works fine. I've tried getattr, getitem, but had no luck. Can anyone shed light on the correct way to do it? Thanks Regards Mark Simpson