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Struggling ABC will try to reinvent itself by adding seven new series this fall, instituting a weekday "happy hour" of comedies and removing Who Wants to Be a Millionaire from its schedule.

ABC executives also pleaded for patience Tuesday while the network tries to rebound from a 23 percent drop in viewership this season.

Meanwhile, the WB network said it will add two new dramas and four new comedies in the fall, and will begin airing regular reruns for three hours on Sundays.

All of the broadcast TV networks are unveiling their fall schedules to advertisers this week. ABC's plans are probably the most scrutinized since the network collapsed to third place last season behind NBC and CBS, and fourth place in its target demographic of 18-to-49-year-old viewers.

ABC's new fare includes a weekly series stemming from the Dinotopia miniseries; a comedy starring John Ritter as the father of two teen-age daughters; and a drama developed by Ben Affleck that gives viewers a chance to win money.

"The core goal for us is to stop the downward trend in our ratings," said Susan Lyne, ABC entertainment president. "We need to stabilize and move the needle a little upwards. Nobody is expecting us to jump into first place next year."

ABC is making changes on every weeknight, and will air family-friendly programs for the hour starting at 8 p.m. on Monday through Friday. Lyne said it sees an opportunity to begin to redefine itself for that market.

The fading Drew Carey Show will shift to Mondays at 8 p.m. Two long-running comedies, Spin City and Dharma and Greg, were canceled, along with the drama Philly.

Who Wants to Be a Millionaire, only two years ago the biggest sensation in television, was left off the schedule. Its dramatic drop in ratings this year  and ABC's failure to anticipate the erosion were the key to the network's decline.

Regis Philbin and Millionaire will return in special events, probably running several nights in a row, much like how the show started. Its executive producer, Michael Davies, had requested this approach.

When football goes off the air in winter, ABC will launch a remake of the series Dragnet on Monday nights.

ABC and the WB have something in common on their new schedules. Both have shows with the same premise: A thirtysomething man time-travels back to high school in the 1980s. ABC's entry is called That Was Then, and the WB's is Do Over.

After successfully remaking the Superman story for a new generation with Smallville, the WB is doing a new version of the comedy Family Affair, starring Tim Curry as the butler. It is also starting a second-generation Batman saga with three crime-fighting women, called Birds of Prey.

The WB is also moving its established dramas, Charmed and Angel, to Sunday nights. Starting at 5 p.m. on Sundays a new hour for networks it will offer reruns of Smallville, the new show Everwood and Gilmore Girls. Executives said the network's primary audience of teen-age girls is underserved by television in those hours.

The WB series Felicity is ending this month, and The Steve Harvey Show was canceled.

Besides That Was Then, ABC's new series are:

--8 Simple Rules for Dating My Teenage Daughter, starring Ritter and Katey Sagal in the comedy focusing on Ritter's relationship with his daughters.

--Dinotopia, a fantasy that extends the concept of dinosaurs and humans living together.

--Less Than Perfect, a workplace comedy set at a TV network. Andy Dick, who once starred in a workplace comedy set at a radio station ("NewsRadio"), is in the cast.

--Life with Bonnie, a family comedy starring Bonnie Hunt as a local TV host.

--Meds, a one-hour drama featuring renegade doctors trying to undercut the frugal HMO that runs their San Francisco hospital. ABC compares its mix of comedy and drama to M-A-S-H.

--Push, Nevada, a drama the network compares to Twin Peaks. Developed by Affleck, it offers clues to a puzzle that viewers can solve to win money.

Other new WB series:

--Everwood, a drama about a neurosurgeon who leaves New York City to set up a general practice in a small Colorado town.

--What I Like About You, a comedy that stars Beverly Hills 90210 actress Jennie Garth as one of two sisters living together in New York City.

--Greetings From Tucson, a comedy about a Mexican-American husband and Irish-American wife, seen through the eyes of their 15-year-old son.