[Zope] scope of DTML-let tag

[Allen Wallis]

Hi,
Say I want to call a dtml method that requires some extra variable, one
way is to set that variable in the REQUEST using REQUEST.set('name',
'value'), and one is able to call the dtml method.
Somebody suggested using the DTML-let tag to do the same thing, but I
haven't been able to get it to work:

<dtml-let variable="some expresion">
 <dtml-var dtmlmethodname>
</dtml-let>

when dtmlmethodname tries to access "variable" with <dtml-var variable>,
zope complains that variable does not exist. Is there a way of using the
let tag to accomplish this, or is there a different way?
Is using the REQUEST object the normal way of "passing" variables to
other methods ?
thanks
Allen