Hi everybody
I'm aware Gianni's last post just above was written 7 years ago, but there's something important to add to his script.
First of all, the script is great because it returns (simply) what has been pressed by the user on the external MsgBox, which is a crucial information when more than 1 button can be pressed in this external MsgBox.
The script runs fine when it's not compiled, but it doesn't work when compiled... unless we add the following line at the beginning of the script :
#pragma compile(AutoItExecuteAllowed, True)
I just found this line in one of Nine's script and it's also in AutoIt help file, at the very end of the topic Running Scripts (chapter "Important notes")