[Zope] Newbie question on page counters

[Richard P. Muller]

I'm in the process of learning Zope hacking, and I'm having a really
hard time getting a page counter to work. It isn't even that page
counters are all that important to me, it's that I feel that if I can't
even do something this simple, what hope do I have doing something
really hard?

Here's what I've done.
(1) Under "Properties" I've created two properties (both ints)
	counter_starting_value, which I've set to 11 (arbitrarily)
	counter_value, which I've set to 0

(2) I then created a DTML method. I spent some time pouring through the
DTML Reference, but I really didn't find a lot on how to modify
variables. Here's what I tried:
<dtml-if counter_value>
	<dtml-let counter_value = counter_value + 1>
	</dtml-let>
<dtml-else>
	<dtml-let counter_value = counter_starting_value>
</dtml-if>
<dtml-var counter_value>

This didn't work. The error message reported that the syntax in the
first (and probably the second, but I never got past the first) dtml-let
command was wrong.

I also tried things like
<dtml-var "counter_value=counter_value+1"> # got a syntax value for
dtml-var here
<dtml-var expr="counter_value=counter_value+1"> #same problem here.

Is there an easy way to do this?

Thanks in advance,

Rick

-- 
Richard P. Muller, Ph.D. 
rpm@wag.caltech.edu 
http://www.wag.caltech.edu/home/rpm