how to  the display of Debit, Credit, and Amount in Currency in USD directly in the Journal Items  

even my base currency is iQD 

for example

i have transaction in usd but system shows debit and credit in IQD because my company currency IQD i want see the debit and credit in usd in journal item? i add compute field and write this code but not work can you give me correct code ? 

Debit field 

result = 0

for line in self:

    if line.currency_id and line.currency_id.name == 'USD':

        result += line.debit

    elif line.amount_currency and line.debit:

        result += line.amount_currency

    else:

        result += 0

Credit field
result = 0

for line in self:

    if line.currency_id and line.currency_id.name == 'USD':

        result += line.credit

    elif line.amount_currency and line.credit:

        result += line.amount_currency

    else:

        result += 0