[Zope] Random Advert Generation

Hey everyone, I have just installed Zope 2 and imported my almost complete site into it. However all my random content generators have gone 'arghhhhhhhhh'. I followed the commands on www.zope.org for producing random content but this doesn't seem to work in zope 2. Here is the code i am using. <!--#var expr="_[_.whrandom.choice(randomMontage)]"--> i have got a property called randomMontage set up of type 'token' with the values: montage1.jpg montage2.jpg montage3.jpg montage4.jpg montage5.jpg now on the old version, a random image would be pulled out and displayed but i am getting a '__CALL__' error now, Does anyone have any ideas, Cheers, Wom.