Lawmakers on Capitol Hill took another step toward deterring phone companies from "slamming" customers--the practice of switching their long-distance service to another company without permission. The House Commerce Committee's panel on telecommunications took up legislation that would require phone companies to get written permission from consumers before changing their service. The bill would allow the FCC to impose fines of at least $40,000 the first time a company breaks the law and at least $150,000 for every subsequent offense. The Senate passed similar legislation in May. The FCC received more than 20,000 customer complaints last year about slamming. The measure also addresses the growth of junk e-mail, known as "spam." The bill would require senders of junk e-mail to identify themselves and list their addresses and to stop sending messages to those who ask to be taken off their list.