Once the holidays are over, the Broadway and Off-Broadway shows begin to fade away. Ivanov and A Funny Thing Happened On The Way To The Forum finish their runs Jan. 4, as will the David Ives' slate of one-act comedies, Mere Mortals. The show will have played 166 performances at Off-Broadway's John Houseman Theatre.

Want a little bit of theatre immortality? Anyone buying a full price ticket between now and Dec. 31 for Mere Mortals can request an autographed poster of the show, signed by current cast-members Anne O'Sullivan, Arnie Burton, Jessalyn Gilsig (who's leaving to do a play at Playwrights Horizons, and will be be replaced by understudy Susan Brady for the last two weeks of the run), Andrew Weems, Willis Sparks and Cynthia Darlow.

Also, full-price ticket holders will receive a voucher entitling them to see the Degas exhibition at NYC's Metropolitan Museum Of Art. (The promotion ties in to the final play of the evening, Degas, C'Est Moi.)

A hit at Off-Broadway's Primary Stages, Mere Mortals moved, in August, to the larger John Houseman space. David Ives' collection of six one-act comedies reopened there Sept. 7 but soon thereafter set about replacing one of its cast-members: Nancy Opel, who was tapped to replace Elayne Boosler in Broadway's Triumph Of Love. Opel's roles, including a demented doctor's receptionist and the wife of a modern-day Degas, are now in the hands of Darlow, who has appeared in such plays as Rumors and Sex And Longing.

Ives is the celebrated author of the one-act comedy compilation All In The Timing. The latest batch of zany vignettes first opened May 6 at his usual home, Primary Stages. The six plays are: Mere Mortals, Speed The Play, Foreplay, Or, The Art Of The Fugue, Degas, C'est Moi, the newly written Dr. Fritz and Time Flies. Initially, a play called The Frogs was supposed be part of the evening, but that has changed. (Oddly enough, a frog is the unseen nemesis of Time Flies, which features a pair of mating may flies who have one night to consummate their relationship before death.) Foreplay follows simultaneous dates on a golf course; Mortals shows construction workers discussing their previous lives over lunch; Speed The Play sends up four David Mamet plays in seven minutes; Dr. Fritz shows an American tourist visiting a South American faith healer; and Degas offers a contemporary New York man convincing himself that for one day only, he is the painter Degas.

Designing Mere Mortals are Russell Metheny (sets), Phil Monat (lighting), Anita Yavich (costumes) and Aural Fixation (sound). John Rando directs.

Ives' most recent Off-Broadway work was The Red Address, a quirky but dark drama about a transvestite getting torn apart by the business world. The Second Stage Theatre production starred Kevin Anderson.

For tickets to Mere Mortals at the John Houseman Theatre, call (212) 239-6200.

-- By David Lefkowitz