Filmmakers JOEL and Ethan Coen were forced to give their new movie NO COUNTRY FOR OLD MEN a period setting on the first day of shooting - when they realised they'd mistakenly cast Josh Brolin and not his father JAMES in a leading role. No Country For Old Men was written as a contemporary production, but when the Coen brothers found out their leading man - who would be playing a Vietnam War veteran - was nearly 30 years younger than they'd expected, they set the picture in the late '70s instead. Writing in American magazine Esquire, the Coens say: "To round out the cast we hired - we thought - rugged everyman Jim Brolin as Llewelyn Moss, the ageing Vietnam vet caught in the middle. "Well, there were some red faces on the set the first day of shooting when Jim Brolin's son Josh showed up to play the part. "Crossed wires, misunderstanding had resulted in our casting office offering the part to an actor who was patently thirty years too young. Talk about a boo-hoo... Too late now though - the contracts were all signed. "Well, that's show business. You roll with the punches. You make it work. How could Josh Brolin plausibly be a Vietnam vet? Simple - set the story in 1980 instead of the present day. A quick huddle with production designer Jess Gonchor and, bingo, we're a period picture."