[Closed] create rollout problem

I forgot from where i found this script, and it work fine when i copy and paste the script to the maxscript editor and evaluate it:

for o in objects do (
o.controller=prs()
if classof o.parent == LinkComposite do o.parent = undefined
)
for o in objects where classof o == LinkComposite do delete o

but when i create a button for it like this:

rollout test "Options"
(
  button btn_DAblock "delete"

on btn_DAblock pressed do
	(
		for o in objects do (
		o.controller=prs()
		if classof o.parent == LinkComposite do o.parent = undefined
		)
		
		for o in objects where classof o == LinkComposite do delete o
	)
	
)

i get the below error from maxscript listener:

-- Error occurred in btn_DAblock.pressed(); filename: C:\Users\jackie.AJMI\Downloads\delte acad test.ms; position: 324; line: 14
--  Frame:
>> MAXScript Rollout Handler Exception:
-- Unknown system exception <<

why is this happen? how to fix it?