Hello, How can I use an undefined variable in an expression? I made a DTML document which gets parameters from the URL, like "/nieuw?maand=1". But I also want it to work when no parameters are given. 'Missing' should be the answer, but the following doesn't work: <dtml-var expr="_.int(maand)+1" missing=1> <dtml-let defmaand=maand missing=1>...</dtml-let> <dtml-in listbydate reverse size=20 start=maand missing=1> I expected to find a solution in http://www.zope.org/Members/michel/ZB/DTML.html http://www.zope.org/Members/michel/ZB/AppendixA.html but couldn't find it. Edwin (who would be so happy with *good* documentation) --- To be upset over what you don't have is to waste what you do have. -- Unknown Surf Edwin Martin's brainwaves: http://www.bitstorm.org/edwin/