design the swimlane activity diagram

Font THE BELOW IS THE PROCESS OF POSTING A MAIL BY A CUSTOMER TO THE POST OFFICE. I A customer shall prepare the post by putting the documents in an envelope. The customer visits the post office and provide the post (envelop) to post officer. The post officer receives the post from the customer. The post officer checks if posting information is complete. If not complete, then the officer returns back to customer to complete information who will provide it again to the officer. The officer checks again the information. But if information is complete, the post officer carries out two activities in parallel that are adding posting stamps and inserting posting information to shipping department. Then officer prints the receipt and provide it to the customer. The customer receives the receipt and do payment to officer. And this is the end. In the light of the above scenario, design the swimlane activity diagram