S Kim wrote:
i want to go.. simple.. but my brain is not working for that now, sad friday.
??
You want to synchronize MaterialA and MaterialB.
As far as I see it the only one simple question which has to be answered is, if the user should have the option to chose MaterialB differently from MaterialA on some occasions.
If yes, some simple scripting would do the job, if no, you only need just one listbox for material.