Jackass” star Johnny Knoxville is officially single.Court documents show a judgment finalizing the dissolution of the actor’s 12-year marriage to Melanie Lynn Clapp was entered in Superior Court last Thursday. There is no immediate comment from Knoxville’s publicist or lawyer.Knoxville, whose birth name is Philip John Clapp, filed for divorce last July citing irreconcilable differences.The couple separated in July 2006.Reports say 37-year-old Knoxville is asking for joint custody of the pair’s 12-year-old daughter.Custody arrangements and child support were not included in last week’s judgment.Knoxville’s screen credits include “The Ringer,” “The Dukes of Hazzard” and the “Jackass” stunt movies.