Thom Johnson admits he's mystified: Why did Joseph Stein's comedy "Enter Laughing," culled from Carl Reiner's autobiographical novel and opening this Thursday at Ann Arbor Civic Theatre Downtown, fade into obscurity?

"It's strange, because it's such a very funny show," says Johnson, who's directing a 14-member Civic cast in the play, which premiered on Broadway in 1963. "A lot of regional and community theaters used to do it in the '60s. I was in the show when I was in high school, and it just stuck with me. Over the years I was always hoping someone would direct it so I could be in it again."

Instead, Johnson has taken the director's chair in mounting his own "Enter Laughing," which is set around 1950 and deals with Reiner's fictional alter ego, David (played by Dan Roehrig). A young Bronx lad in between high school and college, David's desperate to become an actor - no matter that his parents are bent on his becoming a druggist.

Says Johnson, "David's working in a machine shop part-time, making sewing machines for women's hats. While his parents (Kim Perlman and Jimmy Dee Arnold) want him to go to college, his boss (Jon Elliott)wants him to learn the sewing-machine trade and eventually take over the business.

"But David has his sights set on bigger things. He wants to become a famous actor, in part because he's convinced a star can have his pick of women. He already sees himself as a sort of Don Juan type. He's got a regular girlfriend, Wanda (Jamie B. Platte), and he's also convinced that an acting-school teacher's daughter (Marihelen Hemingway) and a shop bookkeeper (Elise Stempky) have fallen for him."

Squeezed into a three-day time period, "Enter Laughing" bubbles with David's attempts to juggle his alleged harem of females, his panicked preparations for a his first stage role two days hence, as well as his desperate struggle not to let his parents - who loathe the acting profession - find out what he's up to.

Reiner initially rose to fame as an actor/writer of NBC's immortal "Your Show of Shows," the most popular live-comedy series of the early 1950s. (Playwright Stein later gained immortality as script writer for "Fiddler on the Roof"). Ironically, "Enter Laughing" may have been eclipsed by the later popularity of the similar-themed "Brighton Beach" trilogy, by Reiner's friend and "Show of Shows" co-writer Neil Simon.

"That's a possibility," concedes Johnson, who also suggests that a universally panned 1967 film version of "Enter

Laughing" - starring "actor" Rene Santoni in his first and last-ever lead role - may have damaged the stage play's

reputation.

Other Civic actors in "Enter Laughing" include R.J. White as David's guardian-angel pal Marvin; and David Andrews as Marlow, egotistical director of an alleged acting studio. Carl Hanna, Nick Kittle, Wyatt Blackbird, Andy Hoag and Tom Beverly also appear in smaller roles.

"Enter Laughing" depends mightily on its lead character, played by recent high-school graduate Roehrig. "David is in every scene," Johnson notes. "He's off stage maybe three or four minutes, total. But Dan was already off book (i.e. he'd memorized his lines) the very first week of rehearsal. He set a good example for everyone else. David doesn't have all the good lines, but he carries the momentum of the whole show."