Sorry, no more commercials, Vern. Knowhattamean? Ernest P. Worrell, the obnoxious hick spokesman created by Carden & Cherry of Nashville, won't be able to bug his invisible neighbor, Vern, on nationwide commercials anymore. Actor Jim Varney, who has played Ernest in more than 1,000 TV spots for mostly regional advertisers, and the agency have "mutually decided" not to renew his contract, said John Cherry, Carden & Cherry partner. "His reps and our reps decided not to do any more commercials but we are still working together on movies," Cherry said. Varney and the agency will work on a new CBS Saturday morning special, plus a number of movie projects, including "Ernest Saves Christmas," due from Touchstone Films this November, "Ernest and the Curse of the Voodoo King," "Ernest Goes to Jail," "Ernest Goes to the Army," and "Ernest Falls in Love."