NASHUA – Former New York City mayor and presidential candidate Rudy Giuliani vowed to the state's business leaders that he would lower taxes if elected President.Giuliani made his statement at the Business and Industry Association and New Hampshire Political Library's National Leader's Forum yesterday morning at the Sheraton Hotel. The forum, sponsored by Lincoln Financial Group, is intended to bring national leaders to the state to discuss business issues.His call to lower taxes is one policy that Giuliani said he has used to spur economic growth in the country."If you understand how to lower taxes, you understand how to grow...