[Zope] NameSpace Question

I need a name space expert to please answer the following question. Why can't I access row_items in the following senario: dtml document (index): has an input form with records called row_items as inputs. On submit it calls form2 ( post ). dtml document "form2": it uses row_items just fine. it also has an input form and simply calls form3 (post) on submit. dtml document "form3": it cannot find row_items -- i don't understand why, I thought namespaces where stacked on top of each other, can someone help please. Thanks ahead of time, Luis.