Ulrich> "id" is obviously a very bad name for a user variable in Ulrich> Zope. Obvious to who? "id" is a lovely parameter name in Python as long as you're aware you're hiding the rarely used id() builtin. The Zope community seems to be filled with lore that isn't codified anywhere or at best is written down in a sea of howto documents. Ulrich> But I belive your problem will not be solved this way. You Ulrich> probably defined the parameter with "id:int worker_id:int Ulrich> end_date_string", didn't you? Nope. Just the way I indicated: <params>id worker_id end_date</params> no type specifier in the params list, just in the <dtml-sqltest> tags Ulrich> what is the best solution, maybe remove the type identifier at Ulrich> all or try with a default argument id:int=None (id:int=_.None) Thanks, I'll give it a try. Skip