Updating Ref2 in Journal Entry when NumAtCard field in A/R invoice is changed

Hi,

I would like to know for updating ref2 in journal entry when I update the NumAtCard field in A/R invoice.

My problem is

when I update NumAtCard in A/R invoice, didn't update Ref2 field in journal entry.

I also want to update there.

Please advise me how I should do.

Thanks.