Hank Isaly, the CFO of a rapidly growing computer company, notified you, his CPA, that his company plans to go public. The company's stock will be sold on the NASDAQ as well as on securities exchanges in various European countries. He asks if your CPA firm is qualified to audit financial statements prepared under international accounting standards instead of GAAP. He has heard that international accounting standards exist, and assumes that his company's financial statements will have to be prepared in accordance with them. In a related way, he is curious to know more about GAAP standards, and why these are used for US companies.

Write a letter to Mr. Isaly explaining international accounting standards that addresses the above points and the effect that those standards may have on financial statements of his company under the circumstances.

Make sure to fully address his questions and provide additional information that you find relevant to his needs. Use the proper format, effective organization and appropriate style.