Two series to be swept into history

May sweeps kicks off tonight, and this year’s sweeps will see the departure of two long-running comedies and two small networks. UPN and WB will be folded into a single network called CW, and viewers will just have to wait and see which of their favorite series survive this game of programming musical chairs.

Two old favorites begin their countdowns to their season finales tonight. Both “Will & Grace” and “That ’70s Show” debuted in the fall of 1998, when networks were trying to find the next “Seinfeld.”

“Will” and “’70s” featured ensemble casts of relative unknowns that clicked with remarkable chemistry. Both shows arrived with impressive credentials, as well. The Carsey-Werner team behind the popular and critically acclaimed “Roseanne” and “3rd Rock from the Sun” produced “’70s.” “Will” had James Burrows on board, a man whose credits include “Cheers,” “Friends” and “Taxi.”

And both series were upfront about breaking prime time taboos. “Will” may not have been the first show with gay characters, but it was clearly the first prime time network sitcom to feature gay relationships, friendships and break-ups on an equal footing with those of heterosexuals. For its own part, “’70s” did not try to gloss over the drug use of the Ford-Carter era.

For the record, very little controversy ensued.

On tonight’s “Will & Grace” (7 p.m., NBC), friends gather to help Will bury his father, who died suddenly after an argument with Will. This sad milestone offers Will time to do some soul-searching about the direction his life is taking as Grace anticipates the birth of her child and her decision regarding whether to inform the child’s father (Harry Connick Jr.) of the news.

On tonight’s two episodes of “That ’70s Show” (Fox), Hyde discovers that his marriage to an exotic dancer has been a sham (7 p.m.) at the same time that Jackie begins to think of Fez as more than a roommate (7:30 p.m.).

“’70s” will wrap up with a 90-minute retrospective on May 11. “Will” bows out a week later on May 18 with an hour-long clip show followed by a one-hour finale.

Tonight’s other highlights

¢ The Casaya Alliance evicts one of their own on “Survivor Panama: Exile Island” (7 p.m., CBS).

¢ Chris borrows his father’s adult magazine on “Everybody Hates Chris” (7 p.m., UPN).

¢ On two helpings of “American Inventor” (ABC), auditions past (7 p.m.), Judge Mary Lou prods three contestants along (8 p.m.).

¢ On two episodes of “My Name is Earl” (NBC), a hot dog stand restored (7:30 p.m.), Earl returns an item stolen from a bowling shoe (8 p.m.).

¢ Thieves steal key evidence along with Nick’s car on “CSI” (8 p.m., CBS).

¢ Prom night strikes on “The O.C.” (8 p.m., Fox). Lisa Tucker (“American Idol”) guest stars.

¢ Dwight says “just say no” on “The Office” (8:30 p.m., NBC).

¢ A skater vanishes from a rink on the eve of a major competition on “Without a Trace” (9 p.m., CBS).

¢ Diane Ladd guest stars as a grandmother on “ER” (9 p.m., NBC).

¢ An urban crisis calls for action on “Commander in Chief” (9 p.m., ABC).