CBS's soap operas, Guiding Light and As the World Turns, both of which debuted on radio 70 years ago and are celebrating the half-century mark on television this year, have moved on to the Internet. On Wednesday, full episodes of the two soaps, together with those for The Young and the Restless, a relative newcomer (having debuted in 1973), were made available on and on the recent CBS Audience Network, which includes AOL, Microsoft, CNET Networks, Veoh, and others. In a break from the past, however, the online episodes are being sponsored by Gerber, the baby food company, not by a detergent manufacturer, although both Guiding Light and As the World Turns continue to be produced by Procter and Gamble, whose soap products include Dawn, Dreft, Era, Ivory Snow, and Tide.