Senior citizens across Iowa are keeping in touch with their grandkids by using e-mail — they can also catch up with one of their U-S Senators Monday night in a live Internet chat room. The topic is the future of aging in America.Senator Chuck Grassley says this will be his first time to host a chat room discussion. He says it’s on a topic that should be of concern to all Iowans, even those who aren’t yet turning grey.The Hawkeye State has the third-highest percentage of retired persons in the nation and more residents over age 85 than any other state. Grassley says he chose to launch Monday’s town hall meeting in cyberspace to keep pace with on-line Iowans who otherwise might not try to reach him.The chat will be held from 7 to 8 p-m Iowa time on Monday night. Anyone with a computer can participate by logging on to www.politics.com and following the links to Senator Grassley.