[Zope] non static size parameter in dtml-var

I have a dtml-var tag that is being repeated over and over inside of a dtml-in tag. I would like the client to be able to custimize the maximum amount of text output they see, so i did something like the following: <dtml-var "item['title']" size="getTitleLen()"> Where getTitleLen is a method which returns an integer of how many characters max the title is to be. However, when i have this dtml method rendered, i get the following error: a size attribute was used in a var tag with a non-integer value. Is there a do what i am trying to do? If so, how could i do it? If not, why isn't this possible? thanks sRp -- Scott Parish http://srparish.net