NEW YORK -- Kim Delaney, who plays Det. Diane Russell (and Jimmy Smits' snookums) on NYPD Blue, almost chose a different role in life.

"Back in Philadelphia," she explains, "most of the people I knew were either secretaries or got married and had five babies. That was the kind of neighborhood I came from. Court reporting was something a little more exciting and challenging than what everybody else was doing."

But then Delaney took an acting course.

Last spring, she gained admittance to the gritty world of NYPD Blue. Signed to play an undercover cop for the season's concluding four-episode arc, Det. Russell was asked to stay on.

Her character is by turns strong and fragile, dishy and demure, abrasive and endearing. With her brown curls and delicate features, she looked like an angel -- yet she had a problem with booze and a family that was ready to explode.

(On last week's episode, it finally did: Russell's abusive father was shot dead by her mother in a domestic dispute for which her brother was ready to take the rap. tonight at 10 p.m. on ABC and Global, Russell has to pick up the pieces.)

But there was another reason she clicked with viewers - and the show's creative team: The sparks Delaney struck with Smits as the hunky Bobby Simone.

Theirs is a complex and at times raw connection, often warm and caring but never a Be-My-Valentine romance.

"We're not a perfect couple," Delaney happily acknowledges. "Sometimes our relationship takes two steps backwards to get one step forward. We all hope to keep finding ways to keep Diane and Bobby on the edge, so that things don't get predictable."

There's a pause.

"I know what's coming now," she laughs. Yes, here comes that what-is-it-like-to-play-Smits'-love-interest? inquiry.

"He's talented, first off," she replies. "And he's charming. And he's sexy, and he's sweet, and he's a good guy."

And what of those bedroom scenes, perhaps the raciest on series TV? Are they uncomfortable for her? Odd? Fun?

"All of that," she says with a smile. "I just always tell our D.P (director of photography) he's dead if he gets the wrong angle."

Clearly, Delaney has come some distance since her first role -- resulting from her very first audition -- on the daytime soap All My Children. It was back in 1981 that she became Jenny Gardner, whom Delaney describes as "a high school ingenue, a straight little thing." Three years later, Jenny went out with a bang. She died on an exploding jet ski.

"I was ready to leave the show, but they must have figured I was holding out for more money," Delaney recalls. "When my contract was up and I really did leave, they had to write me out fast."

Delaney, divorced with a five-year-old son, looks forward to being part of NYPD Blue "for the duration. This is the perfect series for me."

"And I have NO complaints with what they're doing with my character," she adds. "Like Diane, the characters that I like to play usually have a darkness."

Darkness? With looks like Kim Delaney's, why not roles where she can play the glamor-babe? This question seems to throw her. "I - I - never - I, uh, don't know how to do that," she says. Or at least doesn't need to.