[Gambas-user] Breaking processes

[M. Cs.]

How can I stop the execution of a loop which includes shell command for
copying files?

Example:
PUBLIC SUB FCopy()
DIM i AS Integer
DIM filepaths AS String[]
........................' the array filepaths is filled with contents
FOR i=0 To filepaths.Count-1
SHELL "cp -f  " & filepaths[i] & " /home/destination"
NEXT

END

I'd like to add a Cancel button which would break the loop.Thanks!