tally ies7.2 tallygold

hi,
iam using tally ies7.2, but the problem iam facing is unknowing there is a change in voucher types from jounal to forex journal now I want to convert it back.
now it is not possible.
What should I do now?
is there anyone to help me on the unadjusted forex gain / loss in the tally books at the end of the year in tally.