[Zope] Need Help in Using :record Type in Form Variable

[Tanming Fong]

I've read
http://www.zope.org/Members/Zen/howto/FormVariableTypes
and a few other HOW-TO's and still haven't figured out
how to make use of the :record type in form variables.

My form looks like:
<form method="post" action="processForm">
<input type=text name=choice.1:record>
<input type=text name=choice.3:record>
<input type=text name=choice.10:record>
<input type=submit>
</form>

Now processForm need to tell which and how many choice.x:record are entered.
This works:
	<dtml-var "REQUEST['choice']">
that's as far as I can go. I want to do:
	<dtml-in "REQUEST['choice'].keys()">
		<dtml-var sequence-item>:<dtml-var sequence-value>
	</dtml>
but it doesn't know what "keys()" is.

Question: how do I get the keys and values for this "choice" record in
processForm?

Thanx,
-Tanming Fong