Ok, here it is.
on testclick_(sender)
set mySelectedObject to Backset's selectedObjects()
--set mySelectedObject to Backset's arrangedObjects()
--we can get a count at least
--display dialog (count of mySelectedObject)
set theObject to mySelectedObject's objectAtIndex_(0)
set theValue to theObject's |properties|'s valueForKey_("title")
-- no key "title" it says
display dialog "" & theValue & ""
end testclick_
The line that correctly identifies the object is:
set theValue to theObject's |properties|'s valueForKey_("title")
The selected object in Backset is an object created from the Backupset class. Once you get hold of
the object, you ask its array “properties” for its valueForKey.
HTH,
Craig