[Closed] Problem with listbox.readOnly

Hello everyone.

MaxScript Reference reveals the readOnly -feature of a listbox:
<listbox>.readOnly
When set to true, the user cannot pick items from the list. When false, the user can pick items from the list.

Yet it seems I can’t toggle that parameter. I used this script to test it out:

try(destroyDialog listboxtest)catch()

rollout listboxtest "listbox.readonly test"
(
 listbox testlist "Listbox" readOnly:false items:#("1","2","3")
 checkbox readOnlyToggle "Listbox.readOnly toggle" checked:false
 
 on readOnlyToggle changed value do
 (
 testlist.readOnly = value
 )
)

createDialog listboxtest

The rollout pops up, but when I try to toggle I get this:
– Unknown property: “readOnly” in ListBoxControl:testlist

Anyone see a typo in my script? Or is this a bug?