The procedure of export-import is as followed: First, the exporter (seller) and the importer (buyer) conclude a sales contract with a method of payment (usually a Letter of Credit: L/C). The importer asks his bank to issue a Letter of Credit in favor of the beneficiary (the exporter/ seller). Then, the importer's bank, which is called the issuing bank, asks a bank in the exporter's country, which is called the advising bank) to advise or tell or confirm the exporter about the Letter of Credit. If credit terms and conditions conform the sales contract, the exporter delivers the consignment or goods to the importer through the shipping company or agent. Then, the exporter draws a bill of exchange (B/E) or draft, and presents it together with the shipping documents such as Bill of Lading(B/L) to the advising bank.If the documents and conditions conform the sales contract, it pays the exporter. After that, it sends all shipping documents and B/e to the issuing bank. The issuing bank checks the documents and pays it. Then the issuing bank releases all the documents and irrevocable. While the revocable letter of credit can be cancelled, the irrevocable one cannot except the agreement of the exporter.(Ashley. 2008:155-156; www.Export911.com).