[Zope] empty multiple lists

[Ingo Assenmacher]

Hi everybody,

although this may have been discussed several times:

I added a multiple property to a class, but when I call the instance's
property sheet from the management interface, I get an Type Error,
whenever I did not chose anything from the selection box. That is of
course ok, because there is no property defined within the instance if I
did not select anything. (getProperty(id) fails on None)
How do I create an "empty selection"?

Thanks for your help

BTW: <dtml-call "REQUEST.set('x','[]')"> did not work.