[Zope] test for an object's existence?

[Kevin Howe]

How do I check for an object's existence in the ZOPE tree?

I thought one of these would work:

<dtml-if "REQUEST.resolve_url('http://domain/my/object')">
  Yes
<dtml-else>
  No
</dtml-if>

OR

<dtml-if "my.object">
  Yes
<dtml-else>
  No
</dtml-if>

but they completely die rather than returning a false value.

Is there an "exists" method of some kind?

kh