[Zope] Newbie Question: Create Table Interface

[Roché Compaan]

I'm new to Zope and I have the following problem:

I want to create a interface for creating tables (if there isn't one
already).  The layout of the form would be similar to the form where you add
properties for objects in Zope.

Instead of properties there would be a list of columns and there types and
below that you can type in a new column name and it's type and add it to the
list.  After you have defined the table structure you submit the form and
the table is created.

The columnlist is not a persistant list however.

Question1:
How do you then define a list variable in the dtml document that is only
used while busy with the form?

Question2:
If I add a column to the list, how do I tell Zope to render the same dtml
document and update the list?

Thanks for your help.

Roché