[Closed] instancereplace

I’m pretty newbie about maxscript.
In maxscript ,there is instancereplace method.
So,I want to change to make rollout button and select objects by pushing the bottun.
I tried ,but don’t work well.
rollout MYTool01 “instancereplace”
(
button selectObj_btn “selectObj” pos:[8,5] width:60
button replaceObj_btn “replaceoObj” pos:[8,30] width:60
button replace_btn “execute” pos:[8,50] width:60
local obj=#()

on selectObj_btn pressed do
(
srcobj= $selection as array
)
on replaceObj_btn pressed do
(
dstObj = $selection as array
)
on replace_btn pressed do
(
instancereplace srcobj dstObj
)
Is there a way to find a good code?
Sorry about my poor English.