Jessica Simpson has been sent to boot camp.The 'Dukes of Hazard' star will undergo a gruelling physical training program in preparation for her role as an out-of-work actress who joins the army in 'Major Movie Star'. A source told the New York Daily News newspaper: "She left for Shreveport,Louisiana, on Wednesday. She's going to be in boot camp for two days to learn how to do army drills and salute properly and that sort of thing."In the film, Jessica's character is left devastated after finding her boyfriend in bed with her hairdresser. It has been reported the 27-year-old's celebrity hairstylist friend Ken Paves could make a cameo appearance for the scene. Jessica recently revealed she was prepared to train intensively for her new role.She said: "I want to get really fit for this movie. I am aiming to be able to lift weights in my highest pair of heels!"Meanwhile, Jessica has been allowed to keep the personal trainer she shared with on/off boyfriend John Mayer. She was introduced to trainer Harley Pasternak by John and while she is no longer seeing the music star, Jessica is still working out with Pasternak.The singer-and-actress is said to have dropped at least two dress sizes and lost almost 20lbs in eight weeks.Jessica visits the trainer five times a week and her routine includes step-ups, side bends, crunches, dumbbell rows and the occasional use of an exercise ball. She is also on Pasternak's '5 Factor Diet', also favored by other celebrities including Vanessa Williams, Katherine Heigl and Eva Mendes.