Book excerpt: 'Norman Stanley Fletcher, you have pleaded guilty to the charges brought by this court and it is now my duty to pass sentence.' Those words, spoken by a judge to the show's hero in the title sequence of every Porridge episode, are among the most famous in British comedy and they remind viewers that this is no ordinary TV sitcom. The first situation comedy anywhere in the world to be set in a prison, Porridge is about men being punished for crimes committed against the same sort of people who are watching the show. Millions of hard working Britons were fans, many of them anxious about rising crime and worried that burglars would steal the TV set they were watching it on. Yet they still settled down at 8.30pm on Friday nights between 1974 and 1977 to watch a series that celebrates the sometimes pathetic, often ingenious, recidivism of a group of social misfits who by their own admission are failed citizens. How did such a comedy come to be seen as part of a 'golden age of British sitcom', without ever losing its edge to nostalgia? Crime, like sex, sells. But Porridge did not romanticise villainy. Written by Dick Clement and Ian La Frenais, it's a satire of class-consciousness and power, warmed by a humanistic celebration of men on the margins of society. Its heroes are weak inadequate misfits, not tough, glamorous gangsters. Porridge was a success because the essence of situation comedy is confinement; characters in this format are people who feel trapped and thwarted by circumstances beyond their control. This, therefore, is the ultimate sitcom. Richard Weight's entertaining study of this much-loved classic places Porridge in the context of 1970s social upheavals, explores how the series satirises structures of class and authority through Fletch and Godber's battles to outwit the prison officers Mr Mackay and Mr Barrowclough, and traces its influences on TV comedy that followed.