In a world where most programmes are recorded and perfected before they reach our screens, it is hard to imagine an era when every radio and TV programme went out live. The actors and actresses who worked in the BBC's first television studios at Alexandra Palace had - literally - to think on their feet, running from set to set, often while changing costume and making cuts to their scripts at the same time. In "Do Not Adjust Your Set", Dame Eileen Atkins, Wendy Craig, the late Sir Nigel Hawthorne and other old broadcasting hands recall the frenetic conditions in which such television classics as "Dixon of Dock Green" and "Z Cars" were made and the extraordinary hazards they had to deal with.