A SALES agent, sentenced to 100 hours' community service for forging a signature, failed to prove her conviction was unsafe. Lo Pui-ying, 30, had denied a charge of uttering a forged document but was found guilty after trial. High Court judge Mr Justice Kaplan heard that Lo worked for the American International Assurance Company (Bermuda) Ltd (AIA). On November 22, 1991, she succeeded in getting a woman to sign a life and medical insurance form. But a few days later the client decided to cancel. On November 28, AIA received an amendment purportedly signed by the client indicating she accepted the insurance, but the signature was found to be a forgery.