[Zope] problems with <dtml-in> (sort_expr)

[Luis Martin Arganaraz]

Hello everybody.
My problem:
I want to reuse a dtml-method ("myMethod") that manage tables. In 
"myMethod" I have the next piece of code:
	<dtml-in list_of_dictionaries sort_expr=sort_by ...>
where "sort_by" is has the "column" to sort. This work fine, but now I want 
to use "myMethod" to show a table and I don't want to sort it.
Which is the value of "sort_by" that do what I want?

I have been looking the answer on the ZopeShelf, on the mailing list and I 
haven't found it yet.
Any suggestions?
Thanks,
Martin