CBS Orders More Episodes of Jenna Elfman's "Accidentally on Purpose"

CBS picked up five more episodes of its rookie Jenna Elfman comedy "Accidentally on Purpose" on Tuesday.

The show, in which Elfman plays a film critic who gets pregnant after a one-night stand, has been a solid performer on Mondays, a night where the ratings bar is set very high.

Although "Accidentally" has been the lowest-rated performer of the lineup, it has gradually retained more viewers from its "How I Met Your Mother" lead-in.

The order brings the complement to 18, short of the 22 episodes for a full season. This is mainly due to CBS still having episodes of "Rules of Engagement" for later this season.

Fall TV Premieres: Monday Night

Today marks the official start of the 2009/2010 Fall TV Season, even though we have seen several shows premiere throughout the networks since August.

It is a busy Monday with several returning favorites and some exciting (and not too exciting) premieres. Here's a run down on what's new (or returning) to the "tube" tonight:

ACCIDENTALLY ON PURPOSE (CBS 8:30 pm): Jenna Elfman returns to TV as Billie, a film critic who gets knocked up from a one-night stand with a younger man (Jon Foster) while she's broken up with her boss/boyfriend (Grant Show).

THE BIG BANG THEORY (CBS 9:30 pm) - The 3rd season premieres with Leonard (Johnny Galecki) the experimental physicist and Sheldon (Jim Parsons) the theoretical physicist sharing their "geeky" life with their neighbor, Penny (Kaley Cuoco), the attractive blonde waitress with show-biz aspirations.

CASTLE (ABC 10:00 pm): Author Richard Castle (Nathan Fillion) returns for a 2nd season as works with NYPD homicide detective Kate Beckett (Stana Katic) as they reopen the case of her mother's murder.

CSI: MIAMI (CBS 10:00 pm): On the 8th season opener Eddie Cibrian joins the cast as Jesse Cardoza who will replace Erick Delko (Adam Rodriguez) after his encounter with an alligator. The show will flashback to 1997 when Horatio (David Caruso) built his team.

DANCING WITH THE STARS (ABC 8:00 pm): The 9th season premiere with 16 new "stars" including Donny Osmond, Debi Mazar, Macy Gray, Ashley Hamilton, Melissa Joan Hart, and Kathy Ireland.

HEROES (NBC 8:00 pm): On the 4th season premiere the heroes are freed to go back to living their normal lives including Claire (Hayden Panettiere) enrolling in college, Peter (Milo Ventimiglia) returning to his paramedic duties, Hiro (Masi Oka) discovering he's seriously ill, and Nathan (Adrian Pasdar) returning to his political roots, but his inner Sylar (Zachary Quinto) slow emerges.

HOUSE (FOX 8:00 pm): The 6th season premieres with House (Hugh Laurie) being held against his will in a mental hospital by his physician (Andre Braugher).

HOW I MET YOUR MOTHER (CBS 8:00 pm): Barney (Neil Patrick Harris) is no less (or no more) arrogant and abrasive now that he and Robin (Cobie Smulders) are entering into a relationship as 5th season premieres.

TWO AND A HALF MEN (CBS 9:00 pm): The long running comedy starts it's 7th season with Charlie's (Charlie Sheen) ex-fiancee Mia (Emmanuelle Vaughier) reappearing in his life while he's engaged to Chelsea (Jennifer Taylor), Alan (Jon Cryer) going through a nervous breakdown after a fling with his ex-wife Judith (Marin Hinkle) and Jake (Angus T. Jones) starting to drive and date.