Multi-Currency Feature
We have "Create JE in"  currency options when a user adds a new record.  Here are the explanation of each type, (I use "TC" for Transaction Currency, "FC" for Functional Currency, and "PC for Presentation currency in below explanation)

"Both Currencies" - User selects a transaction currency, and user can enter debit and credit in any currency and the system will convert the values to another two currencies.  All three currency columns are enabled for user to enter.  But if the JE record is from "Currency Transfer" module, the TC debit/credit columns are disabled, because there is "manual functional currency entry" checkbox in currency transfer, and we don't want the user to enter new values in transaction currency columns and mess up the functional currency fields.

"Functional Currency" - User selects a transaction currency.  Default transaction currency is functional currency, and user can change to different currency.  User can enter either functional currency or transaction currency columns, the program will convert one currency fields to another currency fields.  Presentation currency columns are disabled, and save 0 and won't be converted from TC or FC.  This is for a situation that user only wants to enter JE for functional currency and doesn't want to enter for presentation currency.

"Presentation Currency" - User selects a transaction currency.  Default transaction currency is presentation currency, and user can change to different currency.  User can enter either presentation currency or transaction currency columns, the program will convert one currency fields to another currency fields.  Functional currency columns are disabled, and save 0 and won't be converted from TC or PC.  This is for a situation that user only wants to enter JE for presentation currency and doesn't want to affect functional currency.