It took years for Jenna Elfman to find a vehicle that matched the comedic highpoints of Dharma & Greg, and now she has reached that level once again with the freshman CBS sitcom Accidentally on Purpose. The show centers on a pregnant San Francisco movie critic (Elfman) who lives platonically with the father of her baby, an twentysomething aspiring chef (Jon Foster from The Informants).  The actress recounts struggling to find good material before Accidentally on Purpose came into her life.  The show airs tonight on CBS at 8:30 pm et/pt. (CLICK ON THE MEDIA BAR BELOW TO HEAR JENNA ELFMAN)