Import purchase and payment

We are a Proprietorship concern. We are namely in the Import (Purchase) business and sale it locally. When we import the goods, we make the entry of the purchase and exchange rate of that day, while makiing the payment we use to change that entry on the rate given by the bank. for eg.: Import Purchase --> USD 62.15 (20/02/2014) and Payment made (Paid) ---> USD 60.25 (16/04/2014) is the entries do we post is correct in the books. If not then which entry has to posted for the same? Pls. reply on the above matter.