[Zope] How to create a trigger?

Hi, Sorry for this newbie question. Hope anyone has the time to help me out. I would like to do something like this within a dtml document that has a property: int my_property = 0 <dtml-if "my_property==0"> <a href= .. ???>press this to show some content</a> <dtml-else> <a href= .. ???>press this to hide some content</a> <dtml-/if> ... a bit down in the document <dtml-if "my_property>0"> show some content <dtml-/if> ...or in plain words. I want to set the value of a property ( or variable if that would serve me better ) whenever I click on a link. Can someone please show how to do it? Thanks -- ========================================== Fredrick Rybarczyk Research Engineer NetLab, Lund University