[Zope] adding objects to a ZCatalog

Hi, I have a folder called "images" and a form that to add images to that folder. The form called an external method (../images/addImage) that references a python script, the one I sent earlier, that creates 4 versions of the images in 4 sizes and places them in the "images" folder. Also in the "images" folder I have a ZCatalog called "ImageData". I'm trying to add a line to the python script to automatically catalog any images that are added to the "images" folder. I tried "ImageData.manage_catalogObject..." but I kept getting back: NameError: global name 'ImageData' is not defined. Any advice? Thanks. Tom