DOVER, Del. - Joseph R. "Beau" Biden III, son of Delaware's senior U.S. senator, kicked off his campaign for state attorney general Thursday. Biden pledged not only to prosecute criminals, but also to prevent crimes such as identity theft and Internet stalking of children by sexual predators. "I truly believe that this office has the potential to greatly improve the lives and well-being of the people of the state of Delaware," said Biden, 37, who served as a federal prosecutor in Philadelphia for five years.Biden, a Democrat, will face Republican Ferris Wharton, 53, in the November election. Republicans are banking on Wharton's experience of more than 25 years as a prosecutor to offset Biden's name recognition. Coinciding with the launch of Biden's campaign, the Delaware GOP unveiled a new Web site, http://www.Beausnotready.com.